My uncle built a 377, a 400 with a 350 crank, destroking it, and man will that sob run.H e has it in a 69 chevy pickup and what a sleeper. He outruns everybody in town. I was thinkin of building a 383, but now im thinkin 377.I wanna know of anyone else has buit a similar engine, and what kind of power thier making.

 

Nah, never built one, but built a few 400s. I wouldn't personally give up the cubes voluntarily, but to each his own.

The funny part about building a 377 is that you have to get a special crank that has the 350's stroke (3.48") but the larger main bearing diameter to fit into the 400's block. Or you have to use bearing spacers but I don't trust bearing spacers as far as I could throw them. 377 cranks are certainly not as common as cranks for building a 383 so expect to pay more.

Once you're done doing that you have to get special pistons that are designed to work with the larger 400 bore but with the 350 length crank throws. This is similar to building a 383 but 377 pistons are more rare, smaller selection, and a little more expensive.

You CAN, however, finally use regular old 5.7" SBC rods without having to worry about hitting the block or a cam lobe like you do with a 383 or 400 buildup.

When all's said and done you have an engine with 350-type rev potential, you can use monster valves in the heads without fear of shrouding them against the cylinder walls and of course, 27 more cubes than your garden variety 350.

Worth building? Eh.... Sure. I guess so. Why not?

 

My buddy uses bearing spacers in his 8.80 nova that has a 377 on SPRAY

you can use them fine

Also his car went 10.30 on motor.

i've also noticed that whenever you use a 400 block and build it right, i have yet to see one run better than the other

Tom Guellich 3200lb camaro = 434" 9.80s
Tom Craig 3100lb camaro = 377" 9.80s
Bill Fourtris 3400lb vette = 406" 10.20s
(factor in weight and it had a n2o cam)

thats why i'm building a 377, easy on parts because all you have to rev it to is about 6500 to make good power and that motor can live at 8000rpm so you save parts

build the 377 with either a 5.7" or 6.0" rod
Also 377's are popular and piston availability is abundant and isn't that expensive

 

I used to run a 377. I had TRW bearings that come specifically made for this combo, no spacer needed. 400 pistons for a stock rod will work with a 377 if you use 5.7 rods. Remember, a 400 crank is .250 longer but has .135 shorter rods so you end up with .010 more piston height if you use the 5.7 rod and 3.48 stroke. It's a common misconception that these are super high reving engines. Mine made peak power at 6500 with a 3/8 mile cicle track cam and AFR 220 heads. Medium range power was real nice but low down it suffered but that wasn't its intended use. I now run a 400 with the same heads and a new XR Comp cam and it has much more low end power and it still makes peak power at 6500. It's the breathing components that give an engine its rev characteristics, the frictional losses can only account for so much. Personally I would build a 400. The 3.75 crank fits nice with 6" rods and the extra cubes will make it more streetable.