377 sbc opinons please.

2xmod · Post by **2xmod** » Tue Sep 23, 2008 10:54 pm

On those 377 spacers...Aren they .010 under 400 main bearings with a notch put in them???????? (or something to that effect)

ProPower engines · Post by **ProPower engines** » Tue Sep 23, 2008 11:10 pm

Seems to me the 377 was popular at one time for the most part because the ease of which to find a steel 350 shaft and make some inches cause back then an aftermarket 400 shaft was retarded in cost and a cut down 400 shaft for a 383 was up there as well not to mention block prep and balancing and the cranks still broke.
Now a guy can buy a new quality shaft for a 10th the cost and not rely on old used stock stuff like we did 15-20 years ago.

want-a-be · Post by **want-a-be** » Tue Sep 23, 2008 11:21 pm

Thats very true ProPower.

Don

af2 · Post by **af2** » Tue Sep 23, 2008 11:29 pm

2xmod wrote:On those 377 spacers...Aren they .010 under 400 main bearings with a notch put in them???????? (or something to that effect)

The first ones I used were the TRW bearing. They had no squish and had to be lapped! What a POS! The other one had spacers and was bittchen!
The one I am running is an Eagle with 400 mains. I shift thing 8700 now and I am happy with 30+ runs!

rider8699 · Post by **rider8699** » Tue Sep 23, 2008 11:30 pm

Hear what you all are saying about the extra inches making more power. By the time I get the steel crank I have checked out,I will prob. have almost as much in it as a new scat 9000 3.75 stroke crank plus with the existing 350 crank I will have to use spacers,which adds to the cost also. Took a closer look at the block today,and checked for cracks at the steam holes and found none....but that was with a spot check dye,not a real mag. Will take it to the machine shop to have it checked out and cleaned. As long as there are no issues found I will go from there. If there are issues I will just buy a dart block and build engine as was planned,just thought this engine might hold me over for a year or two for relatively cheap.

kirkwoodken · Post by **kirkwoodken** » Tue Sep 23, 2008 11:35 pm

Chevy Power Book suggested building the 370 with the 400 block and 350 crank. A forged, Tuff Trided 350 crank could be bought new from Chevy for under $80 at that time. 1970-71. They also recommended boring and honing with a deck plate, pointing out that it was mandantory on 400 blocks, if memory serves me.

The Chevy engineers wanted a 400 block in 63, but the bean counters said no. Can you imagine what would have happened with Rochester injected 400's back in 1963?

PackardV8 · Post by **PackardV8** » Wed Sep 24, 2008 11:31 am

The reason GM never built a performance version of the 400" SBC is it would not meet their durability requirements. Think of the bad rep it got for cracking and overheating even as a low-compression, low-output van motor.

thnx, jack vines

ZIGGY · Post by **ZIGGY** » Wed Sep 24, 2008 1:15 pm

377's remain popular in dirt circle track racing because many
think them especially good on slick tracks - soft bottom end off
the corner and power down the straight. With 331, 350, 377, 383 and
406 to chose from, the 377 was hands down slick track choice by my
drivers. I agree that for many applications, it's hard to beat more
cubic inches. Wasn't it Stroker McGurk (showing my age) that said,
"If it don't go, bore it. If it don't stomp, stroke it. If it still don't, chrome it."

clueless · Post by **clueless** » Fri Sep 26, 2008 6:19 am

I was in the same situation a few years ago. My steel cranked 350 had a worn out bore and needed new pistons. The 400 block I had under the bench cost the same to bore as a 350 and pistons were similar in price. To build a 400 I also needed a crank, balancer and flexplate as well as a balance. The new pistons weighed about 2 grams more than my antique 350 domes so I didn't even rebalance, just used the spacers and my old rod and main bearings.

This engine is still going now and I couldn't be happier. Yes it would probably make more HP and Tq as a 400 but I used what I had and it worked out fine.

JMHO

us7race · Post by **us7race** » Fri Sep 26, 2008 8:08 am

My old 377 outran many 406's too...Not all but alot of them in my area..

stealth · Post by **stealth** » Fri Sep 26, 2008 8:56 am

Hmmm…became popular for circle track guys…(became popular years ago)

Factory steel 350 cranks abundant and cheap (years ago before all the custom parts were available at reasonable $$)

400 block bigger bore to unshroud the valves on crappy heads (old Chevy heads-rules etc)

400-406 cid couldn't be fed by existing heads of the time (see above)

Wonder if this had anything to do with it?

SandRacer · Post by **SandRacer** » Fri Sep 26, 2008 9:36 am

Well I thought long and hard about the 377 vs 406 deal when I first started in the drag race scene. Since I was class racing it probably would have been smarter to go with the 377, but I went 406. A buddy of mine was building a 377 and I went 406, same heads, cams ground by UD Harold just for the applications,everything close except my car had to weigh more. Mine always had more top end charge than his. I went on to win many class events so I would probably do it the same way again. The truth is the 377 built just for the class should have been a better choice!

Tom

klw_71 · Post by **klw_71** » Sun Sep 28, 2008 12:07 pm

ZIGGY wrote:377's remain popular in dirt circle track racing because many
think them especially good on slick tracks - soft bottom end off
the corner and power down the straight. With 331, 350, 377, 383 and
406 to chose from, the 377 was hands down slick track choice by my
drivers. I agree that for many applications, it's hard to beat more
cubic inches. Wasn't it Stroker McGurk (showing my age) that said,
"If it don't go, bore it. If it don't stomp, stroke it. If it still don't, chrome it."

Wouldn't almost any big bore short stroke combo give you the easy off the corner power & blow your hair back RPM/hp, these guys want for "slick track"??? how far is too far? Gearing would be the issue here I'm sure.

ZIGGY · Post by **ZIGGY** » Sun Sep 28, 2008 8:35 pm

Klw - I'm not smart enough to argue the technical superiority of a 377 on
a dirt track that is almost icey slick. I just know that many
racers prefer them. May well be just be monkey see, monkey do
or maybe only a mindset (which damn sure can count).
As for the gear part, there are two opposing views.

af2 · Post by **af2** » Sun Sep 28, 2008 11:43 pm

A 377 at 9000 rpm?