I think im gonna build a 377 when i rebuild my engine. What parts do I need? What balancer/flexplate do I need, or do I need custom balanced ones? Also, how strong is the bottom end, should I get something like a main stud girdle? Forged internals?

And what kind of RPM can a 377 do?

------------------

1983 Firebird
TH700R4 Auto
Small Block 400
LG4 ECM, Intake, Carb, Distributor, etc.
Soon to be non-computer.
Clarion Head Unit 45X4
2 Pioneer 400W 12" Subs
Third Gen Performance
"A four cylinder is half an engine."
"Ponies can run, but birds can fly..."

 

I'll just say this: shortening the stroke of the motor is NOT the be-all end-all of building a high revving motor. I ran my short-rod 400 to 6500 RPM (the limit of the valvetrain and cam at the time) on more than one occasion, with usual shift points being around 6000-6200. I NEVER had a bottom end problem and it made great power "upstairs." 13.0s @ 108 in a 3500 lb Malibu with a mild 266* cam, QJet carb, stock converter, 2.92 rear gears and street radials.

I'll tell you this in hopes that you'll really take it to heart: A good flowing set of cylinder heads will make a MUCH bigger difference in your upper RPM power than destroking a motor EVER will.

For super high RPM use (racing) or sustained high speed operation, yes, destroking has benefits in DURABILITY of the motor, but rarely in power.

If you have a 400 block laying around and a 350 crank laying around, then, sure throw together a 377 on the cheap. But if you've got a perfectly good complete 400 short block don't destroke it.

 

Just to add a little to what damon said (and i feel he's right on) is the drivability of an engine designed to make good power at 7500-8000rpms, leaves a lot to be desired on the street.

In order to take advantage of the RPM capabilities, you need a very large cam and high flowing heads, along with very low (numerically higher) rear gears.

All of whick sound cool, but for a daily driver will be a PIA. If you're planning for a weekend only hotrod that you're streetracing or taking to the track for 95% of the time, then go ahead with the high RPM engine, otherwise as damon said, stick with the cubes...you should be able to have a very streetable 12 second car with the 400.

 

Some prerequsites include:

A manual trans, or 3speed auto set up for racing.
Good suspension and somewhat light weight.