427/425, Engine rebuild, Builder say's NEW assembly??

[William B.]

I have an origional 942 block, 427/425 4 bolt main, it has been apart since I purchased the car years ago. Delivered everything to engine machinist, block will clean up at 60 over(no decking), but I have a 454 crank?, Machine shop suggested I purchase a complete blanced assembly, because 427 crankshaft cores are hard to find and I stiil would need new pistons and most likely rods.
Help any suggestions, I do not want a race engine, just a nice driveable 427/425

[William C.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

Lots of cores available, 427, 396 same crank, all forged in the 60's, should not be a problem, just have it balanced. Frankly, with advice like that, I'd be looking for a new engine shop.

[Dick W.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

I have an origional 942 block, 427/425 4 bolt main, it has been apart since I purchased the car years ago. Delivered everything to engine machinist, block will clean up at 60 over(no decking), but I have a 454 crank?, Machine shop suggested I purchase a complete blanced assembly, because 427 crankshaft cores are hard to find and I stiil would need new pistons and most likely rods.
Help any suggestions, I do not want a race engine, just a nice driveable 427/425

Makes a nice 482. Takes a lot of grinding to install a .250 longer arm in a 942 block. Been there done that. Runs like the proverbial "raped ape". Use the '69 L/88 cam and you will end up with about the same idle characteristics as a 425.

There is a Top Flight '66 around somewhere that has that set up. Seems a friend of mine had a 425 about the same time I had mine. He started talking smack about my car..... Never got the chance to make him look bad though. Sold the car before I finished it.

[Keith B.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

you can still buy new 396/427 cranks

[William B.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

Does anyone have suggested purchases with part sources? Assy or buy parts seperate? I am thinking of buying a crank, rods and pistons from NAPA, but wanted to go in with information instead of the counter guy looking for parts not listed in the computor.

[Joe L.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

you can still buy new 396/427 cranks

Keith-----


Yes, you can but not from GM.

[Keith B.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

Joe I was awarer of that. I am not sure what after market makes it but I know its in the speed catalogs. but there are plenty of good used ones out there if you look

[Duke W.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

As long as it has the proper 454 "unbalanced" flywheel and torsional damper, why not leave it as a 454?

Duke

[Joe L.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

As long as it has the proper 454 "unbalanced" flywheel and torsional damper, why not leave it as a 454?

Duke

Duke-----


I agree.

[Clem Z.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

As long as it has the proper 454 "unbalanced" flywheel and torsional damper, why not leave it as a 454?

Duke

you will have to clearance the block like the 454 blocks because of the longer throw.

[William B.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

wanting to restore the car, would have to use the wrong blancer.
I am looking at a 396 short block(3855961) for parts, can use the crank and rods, need new pistons and to have the assembly balanced?

[Joe L.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

wanting to restore the car, would have to use the wrong blancer.
I am looking at a 396 short block(3855961) for parts, can use the crank and rods, need new pistons and to have the assembly balanced?

William------


The difference in the 427 and 454 balancer is very minor and barely discernable. In fact, it's only discernable if someone really goes to a lot of effort. If the 454 crank you have was previously installed in this block, that means the block has already been clearanced for it, so you're ready to go.

Whatever you do, you will need to have the reciprocating assembly balanced.

[Mark Z.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

U can have a 454 internally balanced

[Larry B.]

Re: 427/425, Engine rebuild, Builder say's NEW assembly??

I'd look for a new machine shop. First 427 and 396 crank is the same casting number 6223 . Big block rors are all the same except L88 which had 7/16 bolts. Pistons have to be 427.You mite want to lower the compression from 11 because the gas isn't what it was. Another thought is camshaft.If you plan to drive it alot lower compression and hydraulic lifters will make it a lot nicer to drive. I build alot of engines and I have these cranks.You can call me if I can be any help.541-218-7754