350 vs 366 performance?
 

Here's the deal, my father has two Chevy work trucks from the early 70's. Both are C60 or C70 trucks. One has a 350sbc and the other a 366bbc, I can have both engines for free and they both ran when parked a few years ago. I don't know anything about a 366 engine except that it was mainly used in school buses and dump trucks, or if its even worth pulling. So the question is, which engine should I go with and is a 366 worth building at all? I want to build a good performing street engine w some decent power to replace the ol 307 that is in my truck right now.
Thanks in advance and begin the schooling
NOW
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Re: 350 vs 366 performance?
 

Get the BBC!

Just throw a bigger crank in it!
That'd be cool.

Re: 350 vs 366 performance?
 

We built a 366 for a mud bogging truck about 20 years ago and got it to run well but all we used was the block and crank. Pound for pound the 350 is a better motor. Now if its a 427 truck motor you can make good power with it with a lot less work.
Jimmy

Re: 350 vs 366 performance?
 

The 366 is a low torque engine and aren't good for anything except heavy hauling. I had one and the machinist told me to toss it.

Re: 350 vs 366 performance?
 

350, hands down. You'll be told about making a mega cube BBC out of the 366, but it's just not worth it in all reality. LOTS of $$ to do it.

Re: 350 vs 366 performance?
 

While the mega cube BBC sounds so awesome and appealing, I think it is unrealistic for what I want this truck to do. I'm not going to be drag racing it, ever, well maybe some light to light action but everybody does that haha At least it has a Holley 750 carb on it that was installed right before it was parked. Save me some money there
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Re: 350 vs 366 performance?
 

because the motors were in a big truck would they both have steel cranks in them.The 366 what is the stroke on them are they the same as 396? just a bore change if so the crank may fit into a short deck block and make a real good strong bottomend.

Re: 350 vs 366 performance?
 

I'd take the 366, add 454 peanut port heads, and different pistons to bring the compression up..
and gear the truck low,, like 2:50 low

Re: 350 vs 366 performance?
 

I dont understand taking the 366 and adding the most restrictive BBC heads possible. Just build a .30 over 350(355) and add some stock Vortec heads and 4 barrel Vortec style intake, cam and headers. Then you'll have nearly 400 horses to play with. The 366 just isnt wort the money it'll take to make it worth the trouble/

Re: 350 vs 366 performance?
 

WELL, WE'LL AGREE TO DISAGREE
you can have your 400 hp..
I'll take the 500 ft lb

Re: 350 vs 366 performance?
 

Go with the 350 thats alot of weight for 16 cubes

Re: 350 vs 366 performance?
 

Grab them both, part out the 366 to the machine shop in exchange for some 350 work or parts. Then what the machine shop doesn't want take to the recycle yard and cash in on the weight

Re: 350 vs 366 performance?
 

500lb. ft will be awesome, that Vortec 355 can have nearly that as well. The 366 would be awesome if you want to use tour truck to pull a trailer or something, it's just not a performance engine. My old Cummins (Gen1) made over 700lb. ft. of torque, it was still slow!

Re: 350 vs 366 performance?
 

You, my friend, just hit the nail on the head. That was my initial thought, but I wanted to see what the pros on here suggested.
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Re: 350 vs 366 performance?
 

Wont parts for the 350 be more common and cheaper???

Re: 350 vs 366 performance?
 

Take the 350, and put a reasonable priced 383 kit in it. You'll be glad you did!

Re: 350 vs 366 performance?
 

The 366 is a tall block\long stroke\small bore motor. I'm not sure how big you can bore it but for the cost of some machine work and pistons you could have a pretty big torque/hp motor. Some truck motors were 4 bolt main/steel crank motors. Tall deck intake manifolds are easier to find now and I think truck motors have floating wrist pins. Once you go big block you won't go back.

Re: 350 vs 366 performance?
 

366 has the same crank as a 396 and 427. It is steel and some of the best material made. But a 366 has a tiny bore, awful heads, and is a tall-deck to boot. Take the crank out and sell the rest for scrap. The intake, even though for a Holley, only fits a tall deck-and the Holley carb has a governor in it. The distributor is longer, the exhaust manifolds and accessories don't fit anything but a school bus or big truck, etc. Very little demand in my experience.

The 350 is better, but still old school 2-pc rear seal. I would use it. If you don't mind building something and doing a bit of horse trading; then pull the crank from the 366, sell the 350 running, buy a 454 with a bad crank, build a 427. Now you got power and torque.

Or sell both and/or parts and go buy something fuel injected that is wrecked and do a fuel injected swap. Camaro/Firebird (or Corvette) for Tuned-Port or LT1, Caprice for LT1, 96-99 truck for Vortec. That stuff is out there.

Re: 350 vs 366 performance?
 

The idea of making a 427 is appealing. But this is my first build, and while learning quickly, I still have limited knowledge on engine building. Would the 427 slightly built be more expensive than a built 350? I, however, might have a way of trading for some machine shop work.
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350 > 366
 

In this case, cubic inches per POUND are far more significANT than just gross displacement.
USE the 350.
Unless you intend to spend a giant heap of money building a big block, from the ground up, you will get FAR more performance per dollar, or per pound form the 350.
" The 366 is a waste of cast iron."

Re: 350 vs 366 performance?
 

I believe the 350 is the route im going to take, and with this exact formula. Seems like a pretty cheap way to get ALOT more power than the exhausted lil 307 thats in it right now. Thanks for all of the help

Re: 350 vs 366 performance?
 

Peanut ports arent nearly as horrible as people think they are. It's been a few years since seeing it, but I remember a guy over on 454ss.com putting peanut ports on his BBC chevelle and take it into the 8s.




To the OP, 366s are absolute turds. The only tall deck motor worth owning is a 427 tall deck.