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-   -   While the 250 is pulled... (https://67-72chevytrucks.com/vboard/showthread.php?t=783071)

KevinR 03-10-2019 07:59 PM

While the 250 is pulled...
 
Changing out some gaskets on my 70 250 and decided it’d be easier out of the truck. In any case, with them engine out, what else would you guys be looking at or replacing?

jocko 03-10-2019 09:35 PM

Re: While the 250 is pulled...
 
Check or just go ahead and replace the clutch, pp, release bearing and pilot bushing and at least check the flywheel for heat cracks, replace if necessary (assuming you have a manual trans). Check brake lines while it's easy to see em.

KevinR 03-10-2019 09:48 PM

Re: While the 250 is pulled...
 
Thanks Jocko. Clutch flywheel etc being replaced. U joint and center support being replaced. Planning on water pump and radiator based on age and condition. Debating if I should pull the bed. Engine was running fine when parked last fall but if I have it pulled I want to make sure I cover all my bases.

saxart 03-10-2019 10:06 PM

Re: While the 250 is pulled...
 
If you're pulling the oil pan for a new pan gasket, it might be smart to remove one of the crankshaft bearing caps to see what kind of shape the mains are in if you don't know the history of the engine. In my case this was the deciding factor in NOT putting anymore money into my old SBC (i.e. getting the heads cleaned up, new gaskets, etc.) as the main bearings were discolored and had scratches in them even though the engine ran pretty well.

GRX 03-11-2019 06:55 AM

Re: While the 250 is pulled...
 
While the engine is out and they're easy to get to. Core plugs ... core plugs ... core plugs.
(often erroneously called freeze plugs)

KevinR 03-11-2019 08:59 AM

Re: While the 250 is pulled...
 
Got it, I’ll add core plugs to the shopping list and bearings to the inspection list!

Thanks for the help guys, as suggestions roll in I’ll keep updating my list

Steeveedee 03-11-2019 10:05 AM

Re: While the 250 is pulled...
 
Quote:

Originally Posted by GRX (Post 8484655)
While the engine is out and they're easy to get to. Core plugs ... core plugs ... core plugs.
(often erroneously called freeze plugs)

You know it! They're a lot more fun to replace with the engine out.

KevinR 03-12-2019 10:24 AM

Re: While the 250 is pulled...
 
Any thoughts on head gasket replacement? If yes, any thoughts on head bolt replacement? The ARP studs are $120 and seem a little overkill for a straight six freshening up. Can I just get grade 8s the same length as the bolts I pull?

wpavlis 03-12-2019 09:21 PM

Re: While the 250 is pulled...
 
Front shocks, any rubber seals on the firewall that are going bad. There are likely other things that are easier to get to while the motor is out.

Steeveedee 03-12-2019 10:09 PM

Re: While the 250 is pulled...
 
Quote:

Originally Posted by KevinR (Post 8485442)
Any thoughts on head gasket replacement? If yes, any thoughts on head bolt replacement? The ARP studs are $120 and seem a little overkill for a straight six freshening up. Can I just get grade 8s the same length as the bolts I pull?

You can, but Grade 8 is complete overkill for head bolts, and actually in most applications. If you can get them cheaper than the stock head bolts or ARP studs, go ahead and buy them. The head bolts in these vehicles are not tightened to a specific torque plus some amount of turn- they are NOT stretch bolts, and can be reused many times, in my experience.

saxart 03-12-2019 10:11 PM

Re: While the 250 is pulled...
 
I'm going to ask the obvious question here. Have you done a compression test on this engine yet? Would be a shame to put all of this time and money into a dud of an engine.

KevinR 03-12-2019 10:12 PM

Re: While the 250 is pulled...
 
Thanks! This is a great community. I’m learning a lot along the way (younger ish guy here)!

Greasey Harley 03-12-2019 10:37 PM

Re: While the 250 is pulled...
 
...in addition to what has been listed;

Hoses (all)
belt(s)
motor mounts
battery cables
plugs, wires, cap, rotor (points & condenser if applicable)
fuel filter
oil filter

since you're in there: You might look at the timing chain ...Or are those gears?

Oh yeah, That little rubber grommet that goes around the clutch fork, in the bell housing

I always have a problem with how far to go, and where to stop on these kind of projects.
Good luck, it sounds like a worthy endeavor.:cool:

KevinR 03-12-2019 10:47 PM

Re: While the 250 is pulled...
 
You and me both. It’s always just one more liiiiitttle step

KevinR 03-12-2019 10:50 PM

Re: While the 250 is pulled...
 
No compression test. My feelings are that outside of the labor and gaskets most parts would interchange if the block ended up bad. I would write it off as a learning experience. I’d like to stick with a 250. I’d been driving it for a year as is with no real issues. This all started with replacing a clutch, and led to a little scope creep.

GRX 03-13-2019 01:34 PM

Quote:

Originally Posted by Greasey Harley (Post 8485923)
since you're in there: You might look at the timing chain ...Or are those gears?

^^Good mention. They are in fact helical gears. Larger one at the cam is composite to help reduce vibrations and noise. Replacement is up to you OP. May be a bit beyond how far you want to go at this point. Requires removing side covers, lifters, pushrods, etc.

Did all that with my 250 about 10 years ago when I upgraded to the "marine" cam for a bit more performance. Pretty common back in the day.

KevinR 03-13-2019 03:27 PM

Re: While the 250 is pulled...
 
In my head this is a “Stage 2” of the truck. Stage 1 was steering and brakes to get it around this last summer. This will freshen up the 250 with the idea that it runs til it doesn’t. Then I’ll figure out the final direction...maybe hunt down a 292 for a full build

palallin 03-13-2019 04:50 PM

Re: While the 250 is pulled...
 
Speaking of brakes (if you didn't do this): fresh front brake lines. Much easier to do from the top than the bottom.

KevinR 03-13-2019 05:07 PM

Re: While the 250 is pulled...
 
Done with the disk swap! And you’re right, would have been much easier from the top!

'68OrangeSunshine 03-13-2019 07:01 PM

Re: While the 250 is pulled...
 
Quote:

Originally Posted by GRX (Post 8486264)
^^Good mention. They are in fact helical gears. Larger one at the cam is composite to help reduce vibrations and noise. Replacement is up to you OP. May be a bit beyond how far you want to go at this point. Requires removing side covers, lifters, pushrods, etc.

Did all that with my 250 about 10 years ago when I upgraded to the "marine" cam for a bit more performance. Pretty common back in the day.

If the timing gear is plastic, I would replace it with an aluminum one.

Richard Jensen 03-13-2019 11:03 PM

Re: While the 250 is pulled...
 
If you keep it outside in the winter, I'd say add a block heater. My 350 starts and behaves a lot better on those cold mornings. I've been thinking about a heat pad for the bottom of the 700R4 too.

CastIron 03-13-2019 11:15 PM

Re: While the 250 is pulled...
 
One thing I did when I had my engine out was touch up the paint on the frame, crossmember, and flywheel cover with some Rustoleum. I also washed and waxed the firewall behind the engine, changed over the wiring to run an HEI distibutor (got rid of the resistor wire), and ran a new wire for the electric choke.

KevinR 03-14-2019 02:50 PM

Re: While the 250 is pulled...
 
1 Attachment(s)
Were all these 250s stock with a composite timing gear? Has mine been replaced?

'68OrangeSunshine 03-14-2019 03:34 PM

Re: While the 250 is pulled...
 
Quote:

Originally Posted by KevinR (Post 8487018)
Were all these 250s stock with a composite timing gear? Has mine been replaced?

Depends on the age of the block. I don't know when the nylon gears came in. Possibly, it came OEM, or a rebuilder/PO upgraded to an aluminum gear.
If it's metal, you're good to go.

saxart 03-14-2019 10:19 PM

Re: While the 250 is pulled...
 
Keep us posted on this. I'm curious to hear how it goes for you. Oh, and good luck!


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