scorpion5150

How would these two size up against each other with otherwise identicle build, compression ratios, etc? I am assuming the 377 would be the higher revver, at the sacrifice of torque to the 383? Am I off base? I am asking here guys, hopefully I don't need my flame suit on! Looking towards building a fairly high RPM (7500) street/strip/track engine w/ a possibility of forced induction as well. Getting really mixed answers from my trusted sources, so I turn to the forum!

cv67

And you think youre confused now...
377 will like the higher revs

kwkenuf85

377 will give you the upper rpm power you are looking for. Good luck with your plans!

rube1975

If you want 7500rpm 377ci is the only option

FostersPerformance

The 383 will last longer. Ive built plenty and do this for a living. A 377 also is a stroked 350. The 383 part comes in when you .030 over a 350. A 350 stroked is a 377, a .030 over 350 is a 383.
I know thats not what you meant by a 377, but i just wanted some people to know. Ive had plenty of guys think they have a 383 cause they stroked a 350 without boring it...Then i have to show them the displacement formula.fyi
I own my own business working on boats. Mercruiser makes a 377 stroked 350 that turns 5500 rpm all day and has plenty of power.A very nice motor.My 383 im building right now for my 88 will turn 7000, with power all the way there.
Any motor will survive what you want it to do as long as you throw the time,right parts, and your life savings at it!

chriswtx

I like my destroked 400(377). Runs nice broad torque curve and still pulls up top. I wish I would have went with a bit more compression though. I only went 10/1. Wish I would have went closer to 11/1. Still a great driver though.. 11.7s in the quater mile at 121mph... 440RWHP as well...

CFI-EFI

It all depends on what you want it for. With no other considerations like class rules, certain rpm goals, etc, the only thing that overcomes cubic inches is rectangular dollars. With the 383 you are spending money to make an engine bigger. A laudable pursuit. With the 377 you are spending money to make an engine smaller. Say what???

RACE ON!!!

rick lambert

Me, I'd go with the 383, although we're only talking about 6 cubes, you can gain a few horses, but it all depends on the total package to bring in the maximum HP at the right RPM range.

CFI-EFI

Given equal access to parts for the original choices, I'd go with the 406.

My post, two back, wasn't referring to a difference of 6 cubic inches.

RACE ON!!!

cv67

cristwz-Id like ot hear more on your build. heads,cam, etc..
Were you able to find a crank that didnt require bearing spacers or did you use them ?

C-4 Now

Nice numbers chriswtx! I was wondering what intake on 377. I knew a stock TPI wouldn't go rpms that motor would like!! I presume either you or someone else built intake??

steven mack

Check his sig.

scorpion5150

I too would love to hear more about the build..

ben73

I don't understand why one would build an engine with an rpm target.
Set yourself a HP/Tq goal and work back from there.

If its more of a streeter than a strip car, build it for torque and go for the longer stroke.

chriswtx

400block with Callies billet splayed 4 bolt main caps, 3.48stroke, 6.125" Eagle rods, SRP pistons, Brodix Track 1 heads ported, 236/236 .587 110LSA solid roller cam, comp cam 1.6 roller rockers w/stud girdles, Custom tunnel ram by Jeb, 1300 AZSM mono blade throttle body, 26lb injectors, Hooker headers, B&B 3" LT1 exhaust, 4.11 gears. Motor was built in my garage and all other work was done by me except for the intake which I designed and Jeb welded up for me...

chriswtx

No spacers. I used a forged crank with 400 mains and a 3.48" stroke...

scorpion5150

Just seeing it gets me excited!! Just out of curiousity what rpm are you shifting at? How far have you revved her?

hexane

I've been thinking about the 377, but that might be just a bit too much for my pocket book for now. I'm particularly interested in the "350 GM should have built." Supposedly its a 400 block with a 3.25" 327 crank, 6.2x" Ford 300 ci rods and can make over 450 hp with a very flat tq curve even with a mild cam and crappy 87 octane gas. Its also amazing how they were able to build it for under 3 grand. That could be an option for the future if I could find the article again....

chriswtx

My cam is a bit on the small side, so I shift at around 6800-7200. But it revs pretty easy to 7500rpm. I will be switching to a bigger cam soon. Looking at something like a 242/250 .620lift on a 112 or 114LSA. It should really make an improvement on the current cam...That or I might add a small shot of NOS like 150hp or so for fun...

JAKE

One of the mags beat you to it. A few years back they built two SB Chevy street engines, one a 377 and the other a 383. Built them as identical as they could. Same camshaft, intake, etc., and the timing and jetting were optimized on both engines.

Both were dynoed with temps held the same, etc., etc. The purpose was eliminate as many variables between the two engines as possible and to see which would make the most power; shorter stroke but bigger bore Vs longer stroke but smaller bore.

I'm going from memory of this because it was a while ago, but the 383 made more HP and Torque all the way from down low to somewhere around 5000 (maybe a tad higher), then the 377 passed it and continued the power lead for another 500 rpm or so.

The torque of the 383 made it the better all-around street engine but the article concluded "You can't go wrong going either way", or words to that effect.

Jake