I'll try and keep this short as possible guys.I finished rebuilding the top end of my engine this spring .The thing ran great untill the other day when i noticed a bad knocking noise,think the bottom end is letting go somewhere.Anyway,i located an old 350 from a 1500 series pickup('74),i did a few tests to the thing and it seemed to be pretty sound for the age.I also had my sbc book with me and the no's on the block indicate a 4-bolt main block used for heavyduty and high-performance applications(3970010).The problem stems from a lack of money.I plan to re-use all the parts i put on the bad engine on the 350(94' tpi heads,cloyes double roller timing set,summit cam,lifters,305 h.o.alum. intake.,waterpump,starter,etc.)The bad engine is a '73 307 so i know everything will fit .I'd love to be able to take the 350 to the machine shop,but the money isn't there.I've got the heads off the 350 and things look good,no ridge,head gaskets were intact,not much carbon build-up anywhere.I plan to check the bearings when i get it on a stand.If they need replacing i'll do it.Have any of you guys done a "junkyard jewel"build-up like this?Would you take a chance on a high-mileage motor like this?Any suggestions or success-failure stories would be great..thanks!

 

If the parts are relativly new you are swapping on, I don't see any probs. If you really must re-use the cam make sure to put the lifters back in the same holes they came out of. I would just replace the cam though. Use plenty of kerosene to flush out the motor. This is a good cleaning agent and wont damage the bearings. Keeping it clean is most important...

 

Thanks for the input.I normally would replace the cam if it had any age on it at all,but like i said ,these parts are virtually new,i don't think i put 1000 miles on the car since i did the work.I was planning to keep the parts matched so the wear paterns would stay the same,but thanks for the reminder.The kerosene was a good tip,never used it for this before.While i'm hear ,does anyone think the tpi heads i'm using are a little harder on the bottom end and might have contributed to my other motors failure?Going from a 76cc smog head to the 64cc tpi heads is bound to move compression up some,but i don't think this would hurt a healthy engine would it?People run aftermarket heads with alot more squeeze than these heads have.The 350 should be able to handle these mild parts with ease i would think.Anybody else have some input?

 

Two things I absolutely would replace since you've got the engine on the stand are cam bearings and oil pump. The crank bearings you can check and do what you need to do.

The heads most likely did not cause your problem on the 307 - the originals heads were 64cc, if memory serves. What probably happened is the engine ran so much better that it was run harder - did the same thing to my 396 (top end job w/new cam), didn't change the oil pump or cam bearings, wiped out the rod bearings the first time I got on it - 300 miles after the overhaul.

That truck 350 most likely also has dished pistons, so the smaller chamber heads will help raise compression to a reasonable level.

What is this going into? Both the engines you mention have driver's side dip sticks, which don't get along will with thirdgen exhaust manifolds.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, LT MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/95.5 @ 5800' Bandimere.

 

The motor is going into my '86 Berlinetta,The 307 already had a oil pan with the dip stick going to the pan,rather than through the block,so i'm just going to switch the pans.Funny thing though,the 307 has a much larger oil pump than the 350.I thought they were pretty much all the same(?)Maybe someone used a big block pump?I'm gonna use it anyway because i always had good oil pressure (50-60 psi),even at the end.F.Y.I.,took the 307 apart,found that it was a rod bearing going bad.Nothing let go so everything else should be sound.Wish me luck guys,this thing is being put together this weekend.Everything looks good so far...

 

I will NEVER use a used oil pump again - NEVER! For $20, it just doesn't make any sense.

Think about it: You're taking a pump off of an engine that lost a bearing, and putting it on another engine - if it didn't protect one engine, why do you think it'll protect another?

Get a new oil pump. Then we'll have fewer reasons to wish you luck...

 

Ok Five7,You are 100% right.Gonna hold off on buttoning up the pan until i get a new oil pump monday morning.It would kill me if the same thing happened to me that happened to your 396.This is not something i want to do again right away.Again ,i want to thank you guys for the interest,you might have saved a fellow third-genner some serious headaches.