307 engine rebuild ?

[Ventanakaz]

Has anyone rebuilt their 307 engine ? How much horse power did you get outta it. I was told a 307 is a 283 block with 327 crankshaft. Do you guys think it's possible to get 400 HP out of the rebuild, What's the most you can get outta this engine. I'm thinking of a 383 long block swap, I know for sure I can get 400 HP with an engine from Summit Racing or Jegs High Performance, Was looking a Blueprint engines, What are you opinions. It will probably cost me over 4 grand going with Summit or Jegs, been looking at their long blocks.

[truckster]

How fast can you afford to go? SuperChevy did a 307 build and got 315 HP out of it:

http://www.superchevy.com/how-to/eng...e-performance/

[Warrens69GMC]

307 and 400hp? Nope. go 350 or 383, preferably one piece seal and roller cam

[Ventanakaz]

Originally Posted by truckster

How fast can you afford to go? SuperChevy did a 307 build and got 315 HP out of it:

http://www.superchevy.com/how-to/eng...e-performance/

...Hey truckster, I read the article and think if I had a lighter weight passenger vehicle then this might work, But for my truck I'm looking for 2.02 intake valves and so forth, and maybe the aluminum heads, 4 bolt main, Thanks for the link, it was a good read.

[Ventanakaz]

Originally Posted by Warrens69GMC

307 and 400hp? Nope. go 350 or 383, preferably one piece seal and roller cam

...Yap that's where my thinking is headed, I looked at more than a few engines on Summit and Jegs, I'm looking to swap over from my 307 the eldelbrock dual plane intake manifold with the eldelbrock 650 carb and Sanderson Ceramic coated mid length headers.

[Ventanakaz]

I'll try to post the link to one of the engines I'm considering, Don't have a computer, Doing this with a Note 9 phone, BTW I'm not tech savvy LOL.

[Ventanakaz]

Here's one of the engines I'm considering, What do you guys think. Gonna mate it up to the 350 TH trans that's already in there, Yah I rather have a 700r4 but I already spent alot of money on this truck, Most of which is the CPP upgraded suspension, Trailing arms, I still have to change out the Cab and Radiator mounts, and install Sway bars front and rear. Almost forgot the rear end pretty much has gone though, changed from stock 3.73 Ring & Pinion to 3.42, one axle had to be replaced because of bearing wear into the axle


https://www.summitracing.com/parts/mll-bp3834ct1/

[special-K]

Do you need 400hp? Have you driven true 300hp? people today are caught up in the numbers when 300hp is more than adequate and quite fun to drive... unless you are jaded. I built a 307 many years ago for a K/20 4spd work truck. It got up and down the road along with or ahead of everyone and when out 4 wheelin' in the mud wringing her out the guys were always asking "What do you have in there?". "307" always raised their brows and loosened their jaws. It also got 13mpg all day long

[Warrens69GMC]

Originally Posted by Ventanakaz

Here's one of the engines I'm considering, What do you guys think. Gonna mate it up to the 350 TH trans that's already in there, Yah I rather have a 700r4 but I already spent alot of money on this truck, Most of which is the CPP upgraded suspension, Trailing arms, I still have to change out the Cab and Radiator mounts, and install Sway bars front and rear. Almost forgot the rear end pretty much has gone though, changed from stock 3.73 Ring & Pinion to 3.42, one axle had to be replaced because of bearing wear into the axle


https://www.summitracing.com/parts/mll-bp3834ct1/

Not a fan of spending all of that money and still have a flat tappet cam.

Better off with this one -
https://www.summitracing.com/parts/m...3ct1/overview/

[siggyfreud]

Originally Posted by special-K

Do you need 400hp? Have you driven true 300hp? people today are caught up in the numbers when 300hp is more than adequate and quite fun to drive... unless you are jaded. I built a 307 many years ago for a K/20 4spd work truck. It got up and down the road along with or ahead of everyone and when out 4 wheelin' in the mud wringing her out the guys were always asking "What do you have in there?". "307" always raised their brows and loosened their jaws. It also got 13mpg all day long

I guess it all comes down to what you're used to. I find my 300hp 350 in my truck to be pretty slow, but I've owned/driven a number of 500+hp vehicles.

If your goal is to cruise or get around town, build towards that goal, and 300hp is probably enough. But if you're like me, like the feeling of acceleration and speed, then that 307 is never going to satisfy you.

But it's also a can of worms, as once you get into higher power you'll want the brakes, tires, and suspension to handle it. That's pretty much why I always do the engine last in my builds, as I want to ensure the rest of the vehicle can keep up once the power is there.

[truckster]

If you're going to spend all that money, I'd start with a true GM Vortec block.

[Ventanakaz]

Originally Posted by siggyfreud

I guess it all comes down to what you're used to. I find my 300hp 350 in my truck to be pretty slow, but I've owned/driven a number of 500+hp vehicles.

If your goal is to cruise or get around town, build towards that goal, and 300hp is probably enough. But if you're like me, like the feeling of acceleration and speed, then that 307 is never going to satisfy you.

But it's also a can of worms, as once you get into higher power you'll want the brakes, tires, and suspension to handle it. That's pretty much why I always do the engine last in my builds, as I want to ensure the rest of the vehicle can keep up once the power is there.

...That's pretty much what I did, Put the engine last, I pretty much replaced all the suspension up front and put new coil springs (brought it back up to stock height) Went with CPP upper and lower Tubular A arms, and replaced the rest up the front suspension with new, Changed the Rear Trailing arms with CPP Tubular trailing arms, Went through the rear end, and replaced original 3.73 gears to 3.42 one of the axles had to be replaced because the bearing wore into the axle, So the rear end is pretty much like new, I have Cab and Radiator mounts that are my next thing to change out, Then after that I have to install my CPP sway bars front and rear, almost forgot, The manual brakes had been upgraded with power brakes with disc up front.

[BCOWANWHEELS]

400hp i really doubt it without radicle parts. 383 aint worth the trouble........ Go 350 2 or 4 bolt main block, a whole lot cheaper. Have you considered a gm crate engine... Hard to beat the prrice plus you get a gm warranty.........

[Ventanakaz]

Originally Posted by Warrens69GMC

Not a fan of spending all of that money and still have a flat tappet cam.

Better off with this one -
https://www.summitracing.com/parts/m...3ct1/overview/

Yes the same here, But this was just one of the engines I was looking at, and I could probably upgrade to roller cam with this one, But there is alot of long blocks to choose from and I have to make sure I get the right one to match up to components and exhaust I have (Sanderson mid length Ceramic Coated headers, Full length 2 & 1/2 inch exhaust pipes running behind the rear wheels. Changed the wheels that were on there (15x8 to 17x8) As I was typing this I saw the link you shared, Didn't see that until I started typing, I'll check it out Warren69GMC Rear Gearing was also changed from 3.73 to 3.42

[Ventanakaz]

Originally Posted by BCOWANWHEELS

400hp i really doubt it without radicle parts. 383 aint worth the trouble........ Go 350 2 or 4 bolt main block, a whole lot cheaper. Have you considered a gm crate engine... Hard to beat the prrice plus you get a gm warranty.........

Yap whatever I choose it will have to be a 4 bolt main, Yah your probably right about the 350

[BCOWANWHEELS]

2 bolt main blocks hold alot of potential, dont sell them short. All 283,s n 327,s are 2 bolt blocks and just look at there capabilitys...... Remember the 327/365hp engine............ Your not building a pro stock all out race eng...............YOUR GONNA HAVE A HEART ATTACK WHEN YOU PRICE EVERYTHING OUT..

[Ziegelsteinfaust]

I helped a friend build around a 325hp estimated 307 years ago with the then practically new Vortec heads. It was in a C10 with 3.42 gears.

I had 9-9.25-1 CR, roller rockers, comp 268 cam, high rise dual plane, and his preferred 600 cfm Carter.

It was on nice motor, and never gave up.

400hp is doable, but would cost more to hit there. A 350 would be cheaper, and get more easier. The short bore hurts potential.

Idle was a bit choppy, but came.on hard at 2500 to 6500. Do to valve float. Other then that it was nice.

[earldub21]

you could do a LS swap for the price you would pay to get 250HP out of a 307!!

[BCOWANWHEELS]

I helped a friend build around a 325hp estimated 307 years ago with the then practically new Vortec heads. It was in a C10 with 3.42 gears.

I had 9-9.25-1 CR, roller rockers, comp 268 cam, high rise dual plane, and his preferred 600 cfm Carter.

It was on nice motor, and never gave up.

400hp is doable, but would cost more to hit there. A 350 would be cheaper, and get more easier. The short bore hurts potential.

Idle was a bit choppy, but came.on hard at 2500 to 6500. Do to valve float. Other then that it was ni

YOUR DREAMING...................

[HO455]

A bit of information here for the open minded.

https://www.jalopyjournal.com/forum/...07-tech.45615/

Nice truck by the way.

[tkeduk8r]

307s are IMO great engines. They get a bad rap, but from a physics standpoint, have a great rod/stroke ratio and with a nice set of heads, machining for a true flat top piston that creates an ideal quench and resulting flame pattern, educated cam selection, tuned carb, distributor, intake and exhaust combo, and ideal gearing can be a lot of fun when you hit the loud pedal AND get better than average MPG numbers for a truck! Remember, gotta look at everything as a package vs. a 400HP engine made to hit peak HP at 5800RPM and 2.73 gears and a 700r4 overdrive will make you question your confidence as a car guy . You can always brag to the high schoolers that you have a factory 283 stroker! Hope that helps!
--Mike

[BCOWANWHEELS]

I agree 307,s are really good. I use them in a lot of sbc army truck conversions I do but in basically stock setup. I don't think you can run 2.02 int valves because it will hit the top of the block though

[siggyfreud]

With the commonality and availability of a 350, there just isn't a lot of reason to sink money into a 307, aside from wanting to be different (which is totally legitimate). Just seems like anything you can do with a 307, you can do cheaper and in most cases better with a 350.

But hey, I say the same thing (at least about doing it better, maybe not cheaper) when it comes to the Gen I vs. LSx debates, so perhaps I just don't have enough fond memories of these engines.

[Ventanakaz]

I appreciate everyone's input and it is helping me with my decision, I definitely won't be having my 307 rebuilt and at first I was thinking 350, then started thinking the 383 stroker, Now I'm back to my original thoughts of 350, I'll try to post another engine that I was just looking at last night (to get your opinions) It's a 350 with under 400 HP, I feel for me and the truck with what I want, That the Torque numbers would be more important. This is the only engine I found so far with my search, that not only has a roller cam but also roller rockers. (Edit) I'll try to post a link so you can read up on it. (Edit 2) Have any of you know anything about ATK engines ? I have been outta the loop for a hell of alot of years, Back in 82 I was a Machinist for a few months at my stepfather's shop. Loved it at that time :-)

[Ventanakaz]

Summit and Jegs (edit) Pretty sure these are the same engines but as you can see they have different HP & Torque ratings.


https://www.summitracing.com/parts/hpe-hp89/

https://www.jegs.com/i/ATK-Engines/059/HP89/10002/-1