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chevy trans


Guest Anonymous

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Guest Anonymous

Im looking at buying a 1978chevy caprice wagon for just about nothing, its got a 350 4 barrel in it, does any one know if there was a long block used in this car? and more importantly what type of trans does it have, the guy said its an auto 3 speed, so does that mean its a 700? any help is appreciated.

kyle

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Umm, a longblock is simply a motor that has heads etc. on it. A "shortblock" is a block that has a crank, pistons, rods, etc. on it but no heads. Maybe not 100% accurate but you get the idea - if this wagon is "complete" it's got a longblock and what you need.

 

As for the trans - the 700R is a 4speed trans. They didn't have those in 78 I don't think. That trans will be 3speed with NO overdrive I'd bet. Not sure which trans it'll be - I'd guess TH350 but with my luck it would be something weird I've never heard of and I'd be wrong. smile.gif

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Guest Anonymous

thanks for the info, yeh i had that whole long block or whatever thing wrong, lol im new to this, does any one know how much it is to rebuild a TH350? thanks

kyle

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Well a few points to make about your possible purchase..

 

If the engine is basically a stock 1978 350 with a 4bbl carb and maybe a cam, its whats called a smogger engine. These engines have poor heads and low compression and generally make small power (by V8 standards). If you are looking for an engine that makes fairly big power, this engine would probably be fine for rebuilding with the right parts to meet your desired power levels. Just understand that if it is indeed a smogger engine from '78..you are probably looking at 180-210HP and maybe 200-250TQ, if its in good shape. These number might be alittle higher if its got an aftermarket cam in it. This WILL move the light Z car with authority, but will be nothing like a mild built 350 making say 350HP.

 

On the th350, these transmissions are proven to be solid and reliable behind engines producing 400+HP when built correctly, and can handle a fair amount of abuse in even stock form when in a light car such as our Z's. They do however have an issue that you need to consider. Because the available finar gears for our cars are on the high side, the NON overdrive th350 will put your engine at around 3000-3400 rpm at freeway speeds..depending on which rear gear and tire height you have. This is not so good for gas mileage, comfort (read LOUD exhaust) or extra engine wear due to higher revs for extended periods of time. The 700r is the overdrive version of the th350 and will drop your freeway RPM's by almost 1000 revs. Many members report 20mpg or better with the 700r tranny. They ARE more expensive to buy and build/modify...but if you have the funds, I would say they are well worth it. I, like you, have a 350 with a th350 combo already. I will probably use the th350 until I can save up and find a deal on a 700r.

 

There is a wealth of knowledge available on these forums. Using the search function will most likely find the info you need to answer 80% of your questions. It works great for me! I'm just starting my first hybrid Z now so we are in the same boat smile.gif

 

Best of Luck!

Jason

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Also, '78' is about the time the "Metric" 350's began popping up. If the car is stock it may have one of those trans in it. The metric trans was only a 3spd auto but had a lock up torque converter in it....GM's intro in to the Overdrive arena; even tho it was not a true overdrive/the lock up converter acted like another gear-thus it had overdrive qualities.

 

Anyway; if its a Metric 350....Run for the hills/not worth messin with! You'ld be better off w/a 200trans-at least its a true overdrive & can be built to a Hi.Perf. capabilities; but then if you're going to that extreme & are running a SBC-then you should at least go for the 700trans-capable of handling more torque.

 

Yes, as said previous-the mid 70's to late 70's were "Smog" engines as GM.Ford,Chrysler were all going thru a metamorphosis in an attempt to obtain "Gas Mileage" thru "lack of power' which means thin casting cyl.heads/blocks & low.perf. everything. You can use the block & crank but you're gonna have to put some bucks in it; by the time your done you could've bought a GM crate engine & obtained real power & durable performance.

 

FWIW!

 

Kevin,

(Yes,Still an Inliner)

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