[greywulf]

I'm looking for a 350 4 bolt motor for my 53 chevy pick-up..Is all 350 4 bolt motors the same or what year of motor should i be looking for.Is there a difference between a 350 4 bolt out of a surburban and a car??Also ...How much difference is there between a th350 trans and a th400 trans...I'm running a 10 bolt posi with 3.08 gearing in the rearend.

Thx in Advance
Greywulf

 

[poncho62]

4 bolt main 350 blocks were available for a number of years, mostly in pickups, Suburbans etc.

A turbo 400 is quite a bit heavier and longer than a turbo 350. Also stronger, but it's debatable whether you always need the extra strength. It also takes more horsepower to turn it.

 

[greywulf]

Thx poncho62.....I have a chance at a 78 Surburban 350 4 bolt...it has a transmission...not sure if it is a th350 or th400 tho.

 

[Ktaves1971]

Greywulf, I probably dont live too far from you. I have a couple 350 engines sitting here, with trannys too that you would be interested in. One is still in the truck and can be driven and tested. Lemme know soon or it will be all parted out.


signed....SBC fanatic Keith

 

[poncho62]

Where you at Ktaves?

I may be looking for a rebuildable 350 in the near future. Don't care if it's 2 or 4 bolt. Us old guys aren't as hard on engines as we used to be................lol

 

[greywulf]

Where you from Ktaves?...I will give you a call


Greywulf

 

[stepside454]

Grey.. just curious, why do you want a 4 bolt ?

 

[greywulf]

Just a stronger motor Stepside454

 

[packratwrecker]

I was always told, that unless you are going to top 500 horse, there was no real benefit, other than braggin rights, by having a 4-bolt block.

With that said, I'm probably as hung up on the 4-bolt fetish as anyone else. There's 3 or 4 lying around my shop right now.

I've seen several IMCA Mods running 2-bolt 350's, usually with good luck. Thas about as hard as anyone's gonna flog a motor repeatedly.

A few spun main bearings, yes, but I can't say I've ever seen a small block come out through the mains. Can't say the same about knotted up rods, though.

 

[stepside454]

Ive seen so many people pay premium for a 4 bolt block, heck people have given me more than they should for 4 bolts..unless your buildin something REALLY stout...or...pulling heavy loads with it.. I wouldnt bother.

 

[67 Deuce 4 Me]

If theres no reason to build a 4 bolt unless your going over 500 hp then why did GM build it in the first place?

 

[stepside454]

for towing purposes a 4 bolt is nice to have when the bottom end is being lugged.
For performance purposes, late 60s & early 70s, some of these motors (LT-1) for example ran over 6000 RPMS out of the box, not counting what people did to them, so they wanted em to stay together. later years it was more marketing than anything, enthusiasts knew the early 70s Vettes & Camaros had 4 bolt mains, so they must be better, so everyone wanted them.
Your best bet is a 2 bolt block, & adding aftermarket splayed 4 bolt caps...but its not a cheap deal.
Ive never broke a 2 bolt block, & Ive run some pretty hard.

 

[Ktaves1971]

Greywulf I tryed to send you a reply from your private message to me but it wouldnt go thru. Give me a call at 519 284 3863 I live about 45 min from you. I am in St Marys.

Keith

 

[ductape&monkeywrench]

old cheavy motors...

Depending on what you want the motor for... there are differnt generations of 350's. The best ones in my opinion are the first generation of 350's (up to early 70's) the only thing that matters with where the motor comes from is the linkage to the transmision. there are two differnt 350 styles: short block (two bolt mains), and long block (4 bolt mains). if you have a small vehicle go with the short block. In the end i would suggest going and talking to mechanics in person. walk into your local auto parts store and pick the brains of the smartest person there. I myself am no pro mechanic like many others here on the web...

 

[poncho62]

First time I have ever seen "shortblock" and "longblock" described that way.............

 

[starnest]

I always look for high nickle content used in late 60s early 70s blocks. This is probably more important than having 4 bolt mains for most applications.

The good news is that almost all of the 60s and early 70s blocks used for 350s were high nickle content. Look for "010" or "020" cast into the side of the block. "010" represents 10% nickle content, this is most common for 350s (in fact all of the 350s I've ever seen from 69 through 73 were "010" blocks - I've seen pictures of "020" blocks).

The high nickle content yields a stronger cast iron block, similar to the way chromium improves the strength of steel.