Thread: high performance 350 chevy buildup???

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WOW dr., that's really close. I read of one fellow who swore he was running 0.018" on a 460 Ford by angle milling the piston crown to eliminate contact as the piston rocked.

Originally posted by tim_bo16
its going into a 1950 chevy pickup and replacing the little 283

wanna sell it?????

sell the 283 or the pickup??? heh... if its the 283.. probably..the pickup no most likely not.. unless i'd get a damn good wad for it.. lol .. but i got another 283 one layin around if ya would be interested in that one too... and i also have the original 216 straight six that we pulled out of it... ( also runs)


umm i also wondered... about the comment with the 400 .. i could also get my hands on a quite cheap 400 (that does run) and is in good condition.. but if i tear it apart and go through it and make a 383 out of it... would there be an even better chance with this combo???

tim_bo, here's the deal. A 350 is made into a 383 by boring the cylinders 0.030" and installing a longer stroke crank such as the one from a 400 small block (3.750" stroke on the 400, 3.480" stroke on the 350). So, if you have a 400 small block, you already have the preferred crankshaft. This 350/383 swap is so popular that there are now aftermarket 3.750" stroke cranks being made by Scat and other companies. Here are some figures to help you:

350, 4.000" bore with 3.480" stroke (stock bore and stroke)
355, 4.030" bore with 3.480" stroke (0.030" overbore, stock stroke)
383, 4.030" bore with 3.750" stroke (0.030" overbore, stroker crank, either from a 400 or from an aftermarket source)
400, 4.125" bore with 3.750" stroke (stock bore, stock crank)
406, 4.155" bore with 3.750" stroke (0.030" overbore, stock crank)

It's all about more cubic inches and a longer stroke for more torque. For a real "hoss" of a small block, rebuild the 400 and use a well-thought out cooling system with adequate radiator size, tight-fitting 360 degree shroud, OEM steel 7-blade 18" diameter fan and thermostatically controlled viscous drive. With its siamezed center cylinders, the 400 tends to run hotter than a 350 block which has water around all the cylinders.

Here's a dumb question.....

If he already has his hands on a 400 engine running, why not just rebuild it as a 400? (plus any overbore adder) If he's not racing it, the siamese cylinders wont matter, the steam port heads he will have for a pattern if he changes the heads to something better, etc.

Seems like making a 383 out of a 350 is good
Seems like making a 383 out of a 400 is not for a street motor

Plus, he can tell everyone that is a rare 283 with too many freeze plugs!

mike

Yep, thanks robot, I just added a last paragraph to head him in the right direction.

well thanks for all the imput guys.. but i dont have the 400.. i said i could get one for cheap.. i know that... i also know that a 400 with a 350 crank makes a 377...?? does anyone know about these??/ i cant remember where i heard about em or seen them.. but i never ever hear about these ...

and by the way.. ya i do kinda wanna keep the small block theme.. simply because i dont wanna have to take out my inner fenders and make custom ones and such..

Originally posted by tim_bo16
sell the 283 or the pickup??? heh... if its the 283.. probably..the pickup no most likely not.. unless i'd get a damn good wad for it.. lol .. but i got another 283 one layin around if ya would be interested in that one too.

the 283's how much?

A 377 is a stock bore 350 with a 400 crank.

lol well... price not really sure... its 1964-1967 block... bored 60 over... umm holly contender intake manifold... less carb... other than that its pretty much stock... so far about 1800 miles on it... i gotta finish puttin all my other mods on my pickup (tranny, rear end gears) before i sell it tho.. cuz im gonna need another engine to put in right away... so what do ya think it would be worth... o and the other 283 is completely stock with the two bbl and all...

[QUOTE]Originally posted by techinspector1
A 377 is a stock bore 350 with a 400 crank. [I /QUOTE]

Tech, Normally when people are referring to a 377 they are talking about a 400 block and a 350 crank. You have to either buy a thicker bearing on the mains or you can buy a spacer which goes between the block and 350 main bearings.
You can buy an aftermarket block which is a 400 block made for a 350 crank. This is a popular motor for race cars. It does not have as much torque but it will turn the RPMs. A 377 is easier to hook up than a 406 or a 383 and it will really turn on top end. this works especially well in a light car such as a Nova where traction might be a problem.

riverhorse, a stock 4" 350 bore and a 400 crank works out to 376.992 cubic inches, or rounded off to 377.

A 400 block with a 350 crank, standard bore (4.125") works out to 372.055 cubic inches, rounded to 372.

A 400 block bored 0.030" with a 350 crank works out to 377.487 cubic inches, rounded to 377.

You're right, the 350 crank in the 400 block used to be a popular swap for those guys who were looking for revs AND more cubic inches. I don't see it being done so much any more, though.

.
Quote Tech
A 400 block bored 0.030" with a 350 crank works out to 377.487 cubic inches, rounded to 377.

I have a good friend just down the road that just built this one with reworked Canfield Aluminun heads and a big stick solid roller cam. It will soon be going in a 91 S10 extra cab. He does all his own machine work. At 68 years old,he thinks this might be his last drag car.But, if his health holds up I doubt it.

Several people here run the 377s as I described in Limited Modifieds( open wheel stock cars).They are easier to hook up with the small tire that they have to run,plus they will turn up quicker and make real good power at higher RPMs than a 383 or a 406.

I have personally never built a 377,but it seems like an interesting concept and I think it would have worked very well in my 2250 lb. Vega that I sold last year.
In a heavy car I would still perfer a long rod 406. Gene

well what about dragsters in about 65-66 with a 377 sbc?? stroker kits possibly???? hehehhe just thought id pick ur brains especially you tech

Originally posted by gassersrule_196
well what about dragsters in about 65-66 with a 377 sbc?? stroker kits possibly???? hehehhe just thought id pick ur brains especially you tech

Yeah, Scooter, they had to be stroker motors because the large bore 400 didn't come out until several years later than that. I can't recall for sure, but it seems like it was '71 or '72.