are all 350 blocks the same?

[AirSpeed]

I'm getting ready to buy a 350 crate engine and want to make sure I don't get something that won't bolt up to my th350. Are all 350 blocks the same? Do any have different bolt patterns? Anything else I need to know before ordering? I'm replacing the 350 in my truck, have no idea if it's the original engine, it does have newer exhaust manifolds so it may have been changed.
Thanks!

[AirSpeed]

Looking at this one, http://m.summitracing.com/parts/nal-12499529

Or this one,
http://m.summitracing.com/parts/nal-12530283

Would one of these be good? Would one be better than the other? It's going in my 72 GMC 4X4 with th350.
Thanks for any suggestions or ideas on other engines! I need to keep the price under $2500 delivered. Thanks!

[AirSpeed]

I'm also wondering what break in oil to buy, apparently these engines don't come with it, any recommendations on break in oil? I've pulled and installed several engines in my time but never a new one so I'm virtuous to all things new engine! Any other things I need to know before ordering? I'm going to use my stock intake, carb and exhaust manifolds and will buy a new water pump. I just want to make sure I have everything on hand, my son inlaw is coming up for the weekend to help me pull the old and install the new, parts store will be closed so I don't want to forget anything! Thanks for any suggestions!

[BruthaMan]

Both of those blocks are very common for replacements in our older trucks. I have the same block, but in the 260 hp version. GM crate motor.

For engine break-in, I've only used Rotella for the few motors I've broken in.

This is what I found a lot of guys were using:

http://www.blueprintengines.com/inde...tappet-engines

Both should be available at your local auto parts store.

Sounds like a fun weekend! Be sure to update us when you get her running!

[NCBowtie]

For break in oil I have used regular 10w30 with Lucas break in additive and also Joe Gibbs break in oil 10w30 with no problems. Both on flat tappet cams.

Make sure you break in your flat tappet cam properly if that's what you will be using.

[69SCSS]

I got the 260hp version too and yea, they don't even supply a break in procedure in the paperwork. Also they don't mention you need the oil filter adapter to put a spin on filter, had to grab the Mr Gasket version. Make sure and clean out the paint from the back of the crank before you seat the torque converter, the paint makes the pilot on the converter to fit... ask me how I know! Just had to crack the engine / trans apart 1/4" to spin the converter to line up with the bolts, wouldn't spin before I did that.
They also don't include the fuel pump plate.

I've heard no complaints about these engines though, just the lack of documentation. Any of these will be a direct bolt on to your TH350, they all have the same bellhousing pattern.

[flashed]

Check JEGS Online ,they usually have them for less ,I got my 260 HP from them delivered for $1207 ,may be a little more now , Im very happy with mine . I also have a 290HP one in my wife's Malibu convertible ,many miles on it .

[mechanicalman]

Originally Posted by AirSpeed

Looking at this one, http://m.summitracing.com/parts/nal-12499529

Or this one,
http://m.summitracing.com/parts/nal-12530283

Would one of these be good? Would one be better than the other? It's going in my 72 GMC 4X4 with th350.
Thanks for any suggestions or ideas on other engines! I need to keep the price under $2500 delivered. Thanks!

They will both bolt right in to the bell housing, the engine mounts, and water pump but the L31 will require a different intake manifold. It has a 1 pc rear main seal requiring a different flex-plate with a counter weight with same number of teeth your present flex-plate has, and requires a special distributor gear due to the roller cam, plus it does not have internal thermostat bypass circuit so you will need to route one from the intake to the w/p. The accessory bolts on the heads are different on an L31, depending on your brackets that could also be a problem. And I'm pretty sure it will not accept a mechanical fuel pump due to lack of machine work on the block and lack of a fuel pump eccentric on the camshaft. Contact the seller to be sure but I've never seen an L31 with those provisions.

Good news is you can use a later model serpentine belt system 87-95 from the junk yard and it will fit as opposed to the gen 1 engine needs a special expensive GM R side bracket or a drilled hole in the head. The serpentine kits in the GM performance parts catalog have that special bracket.

If you don't mind using an electric fuel pump, new flexplate, new dist gear, t-stat bypass hose and new intake manifold, and can deal with the accessory bolt pattern, I'd use the L31, it's a stump puller and won't leak oil.

The 290HP will have less torque but more high RPM HP. IMO, it's over-cammed for it's compression ratio and has the old 2pc rear seal and rough valve cover gasket surfaces. They tend to leak a little oil, if that's an issue with you. But it's a cheaper install and all the parts you have now will fit.

Kinda depends on what gearing you have for the 290HP and if your budget will allow the L31.

[jocko]

Concur with Flashed - if you want the 290 hp motor, wait for it to go on sale at JEGS if you can. It happens often (or, at least the 260 hp version does - but I THINK I've seen both versions on sale at different times).

If you want simplicity - go with the 290 hp version - it is as close to a direct replacement as you can get (but with a bit more power than stock...) and all the accessories are a simple bolt-on in the same places. The L31 has some differences that mechman outlined very well (thank you!). I think the one piece rear seal is a bonus feature on the L31, but I (personally) don't like center bolt valve covers (I know, it's a stupid pet peeve of mine ) So, if you want to paint it all orange and make it "look" original, then I'd go with the 290 hp setup and accept that someday, someway, you'll eventually get a rear main seal leak. It may not happen tomorrow or in the next 10 years, but it will happen before the L31 motor leaks. If you don't care about original "looks" then the L31 is most likely your best value. Trucks need torque, not necessarily hp, so that's another check in the L31's favor.

[jocko]

Also - keep in mind that the L3 has a $100 core charge... (290 hp motor doesn't) I am not fond of shipping long blocks around the country to save $100. So, if that makes a difference in your price comparison, just thought I'd throw that in.

[AirSpeed]

I just ordered the 350/290 hp engine. They weren't going to ship it unless it was to be used in a pre 1966 vehicle or off road vehicle because of California laws, told them it's going in an off-road dune buggy! Didn't even have to pay sales tax!

[jeffahart]

Well, for me that's just one more reason to get a local build, and maybe even do it myself now. None of their business to have documentation on what's under my hood. I met their smog requirement by buying a 1970. I don't look at mid 70s or later project vehicles to get around the smog checks. Now their putting the squeeze on a 290hp V8. What are you supposed to put in a truck. Maybe they think a EcoGreen Turbo 4 cylinder should do the job. It's a truck, it needs power, lots of power.

They just sold me on 383 (there you go Cali Greenie, I'll stroke you right back). That way I can get out of this state faster!!!

more coffee........ I'm hyping out after I read that!.......

[mechanicalman]

Originally Posted by jeffahart

Well, for me that's just one more reason to get a local build, and maybe even do it myself now. None of their business to have documentation on what's under my hood. I met their smog requirement by buying a 1970. I don't look at mid 70s or later project vehicles to get around the smog checks. Now their putting the squeeze on a 290hp V8. What are you supposed to put in a truck. Maybe they think a EcoGreen Turbo 4 cylinder should do the job. It's a truck, it needs power, lots of power.

They just sold me on 383 (there you go Cali Greenie, I'll stroke you right back). That way I can get out of this state faster!!!

more coffee........ I'm hyping out after I read that!.......

X2. We don't need more government in our lives, we need less.

[leddzepp]

Originally Posted by AirSpeed

I just ordered the 350/290 hp engine. They weren't going to ship it unless it was to be used in a pre 1966 vehicle or off road vehicle because of California laws, told them it's going in an off-road dune buggy! Didn't even have to pay sales tax!

Nice

[AirSpeed]

You guys have any suggestions on intake and exhaust gadgets? I don't want pull it apart again.

[leftybass209]

Congrats on your motor purchase! I have that same motor, but it was a bit older and I've had some work done to it. A good dual plane from most any manufacturer is what that engine was designed to use. It's not designed for any top end performance and starts to level off dramatically in higher RPM's. If you'd like some interesting reading for that particular motor (the only difference between the 260HP and the 290HP Crates is the camshaft), check this link out. It outlines everything done to these motors to squeeze the most HP/TQ out of it one step at a time. http://www.superchevy.com/how-to/463...-engine-build/

On another note, I don't know why they wouldn't ship unless it's for 66 and older, as our laws state 1974 and older don't have smog requirements.

[AirSpeed]

I'm going to the parts store to get all the stuff I need but don't want to forget anything.
So far I've thought of - new water pump, intake & exhaust gaskets, oil and filter but not sure which oil. New belts, permatex, new hoses, new motor mounts, I want to replace as many parts that wear now so I don't have to do it later! I just installed new plugs a few weeks ago, should I reuse those or get new plugs as well? What else might I need from the parts store? I'm sure I'm forgetting something.

[AirSpeed]

Originally Posted by leftybass209

Congrats on your motor purchase! I have that same motor, but it was a bit older and I've had some work done to it. A good dual plane from most any manufacturer is what that engine was designed to use. It's not designed for any top end performance and starts to level off dramatically in higher RPM's. If you'd like some interesting reading for that particular motor (the only difference between the 260HP and the 290HP Crates is the camshaft), check this link out. It outlines everything done to these motors to squeeze the most HP/TQ out of it one step at a time. http://www.superchevy.com/how-to/463...-engine-build/

On another note, I don't know why they wouldn't ship unless it's for 66 and older, as our laws state 1974 and older don't have smog requirements.

Thanks! I'm excited to feel a fresh engine in my truck! The existing engine was rebuilt long ago, smoked once in awhile and was fairly tired. I don't know why they go back to 66, the girl kinda emphasized that "you're using this engine in a pre 1966 vehicle aren't you?", that was after I mentioned my truck being a 72. I'll be using the stock intake and quadrajet. Thanks!

[Fitz]

Originally Posted by airspeed

Are all 350 blocks the same?

no!

[dfrank]

Originally Posted by AirSpeed

I'm going to the parts store to get all the stuff I need but don't want to forget anything.
So far I've thought of - new water pump, intake & exhaust gaskets, oil and filter but not sure which oil. New belts, permatex, new hoses, new motor mounts, I want to replace as many parts that wear now so I don't have to do it later! I just installed new plugs a few weeks ago, should I reuse those or get new plugs as well? What else might I need from the parts store? I'm sure I'm forgetting something.

You will need an oil filter adapter to use a spin off oil filter. I use Bradd Penn break-in oil, but not many part stores carry it. What part store are you going to? I can look it up and see what break in oil they carry and then make a suggestion.

[leftybass209]

Originally Posted by dfrank

You will need an oil filter adapter to use a spin off oil filter. I use Bradd Penn break-in oil, but not many part stores carry it. What part store are you going to? I can look it up and see what break in oil they carry and then make a suggestion.

I have the same engine and I didn't need an oil filter adapter to use the spin style.

[mechanicalman]

Originally Posted by leftybass209

I have the same engine and I didn't need an oil filter adapter to use the spin style.

Not sure what year Airspeed's truck is, if it's a 67 it would need an adapter but if 68 and above the adapter can come off the old engine if it's a SB V8.

[jimbosprint]

Originally Posted by mechanicalman

Not sure what year Airspeed's truck is, if it's a 67 it would need an adapter but if 68 and above the adapter can come off the old engine if it's a SB V8.

This. I got mine off the old engine (1972).

But I forgot to take it off before I put the old engine into the crate the new one came in. Took me almost an hour to uncrate, bolt the hooks back onto heads, hoist up into the air, get oil filter adapter, and crate old motor back up.

[mechanicalman]

Originally Posted by leftybass209

Congrats on your motor purchase! I have that same motor, but it was a bit older and I've had some work done to it. A good dual plane from most any manufacturer is what that engine was designed to use. It's not designed for any top end performance and starts to level off dramatically in higher RPM's. If you'd like some interesting reading for that particular motor (the only difference between the 260HP and the 290HP Crates is the camshaft), check this link out. It outlines everything done to these motors to squeeze the most HP/TQ out of it one step at a time. http://www.superchevy.com/how-to/463...-engine-build/

On another note, I don't know why they wouldn't ship unless it's for 66 and older, as our laws state 1974 and older don't have smog requirements.

You bring up an interesting point, leftybass. That's a 560.00$ camshaft!

http://m.summitracing.com/parts/nal-12499529 2069.97$

http://www.summitracing.com/parts/na...7353/overview/ 1509.97$

For the price of the 290HP engine, you could get the Jegs 260HP bundle that comes with HEI, intake manifold, dampener, intake gaskets and still have room left over for 141.04$ worth of camshaft! And assuming the 260 has never been ran, you don't even need new lifters! And it would be within the budget to upgrade the timing chain as well.

http://www.jegs.com/i/Chevrolet-Perf...06#moreDetails 1928.93$

http://www.summitracing.com/parts/su...make/chevrolet 71.92$ shipped, works with stock converter, IMO better than the cam in the 290HP for this compression level. Check out the reviews on people who have got this cam from summit and put it in a 260HP.

Heck let's throw in a name brand double roller timing chain
http://www.ebay.com/itm/Competition-...3b508b&vxp=mtr 28.99$ shipped

Rubber with steel core fel-pro timing cover gasket
http://www.summitracing.com/parts/fe...make/chevrolet 7.97$

Water pump gasket (X2, sold as single, .97$ each) 1.94$
http://www.summitracing.com/parts/fe...make/chevrolet

That leaves 30.25$ for pan gasket. You could get a nice fel-pro 1pc gasket from summit somewhere between 20-30$ (not sure which one fits, they would know what fits the 260HP). And if between the cam and gaskets if you exceed 99.00$ you will get free shipping on everything. You could always bump it up over 99$ with some break-in oil or something else you need to buy anyway, like maybe clamps, etc.

That's a lot more engine for the money of a 290HP.

[AirSpeed]

Originally Posted by mechanicalman

You bring up an interesting point, leftybass. That's a 560.00$ camshaft!

http://m.summitracing.com/parts/nal-12499529 2069.97$

http://www.summitracing.com/parts/na...7353/overview/ 1509.97$

For the price of the 290HP engine, you could get the Jegs 260HP bundle that comes with HEI, intake manifold, dampener, intake gaskets and still have room left over for 141.04$ worth of camshaft! And assuming the 260 has never been ran, you don't even need new lifters! And it would be within the budget to upgrade the timing chain as well.

http://www.jegs.com/i/Chevrolet-Perf...06#moreDetails 1928.93$

http://www.summitracing.com/parts/su...make/chevrolet 71.92$ shipped, works with stock converter, IMO better than the cam in the 290HP for this compression level. Check out the reviews on people who have got this cam from summit and put it in a 260HP.

Heck let's throw in a name brand double roller timing chain
http://www.ebay.com/itm/Competition-...3b508b&vxp=mtr 28.99$ shipped

Rubber with steel core fel-pro timing cover gasket
http://www.summitracing.com/parts/fe...make/chevrolet 7.97$

Water pump gasket (X2, sold as single, .97$ each) 1.94$
http://www.summitracing.com/parts/fe...make/chevrolet

That leaves 30.25$ for pan gasket. You could get a nice fel-pro 1pc gasket from summit somewhere between 20-30$ (not sure which one fits, they would know what fits the 260HP). And if between the cam and gaskets if you exceed 99.00$ you will get free shipping on everything. You could always bump it up over 99$ with some break-in oil or something else you need to buy anyway, like maybe clamps, etc.

That's a lot more engine for the money of a 290HP.

Now Ya tell me!