I have a 67 400 and a two 455's. Going to rebuild one of them to put in my 67 Cutlass convertible project. Its not a 442 so engine choice isn't an issue. I would kinda like to put the 400 in just because its a 67 400. But then I think selling the 400 to help pay for a 455 rebuild makes more sense. After all, unless your a Olds guy the 400 and 455 are just big blocks. Its not going to be a big build. Mild build-up like the one I did in my 67 f85 post. Very happy with that one. Thoughts?

 

Sell the 400 and build a 455. The 400 is worth more as it's a 442 only motor and the 455 will make more power so it's a win/win. You will probably have guys on here shortly with old war stories of how their 400 spanked 455's back in the day. That may have been true but built from scratch equally (same compression, heads, intake etc.) the 455 will make more power and at a lower RPM which is exactly what you want in a nice street cruiser.

 

Sell the 400 block and the 455 crank and rods and make a 425 out of what is left.

Better yet.

 

I have to disagree with that. Pistons and rods are more readily available for the 455 and they are cheaper to boot. Then in the end you are still down 30 cubes for no good reason.

 

The 400 has a forged crank. The 455 does not.

 

100% true but unless he's planning to build a 600+ HP race motor that gets beat on like a red headed stepchild at the track that is a non issue. The car in my avatar has a cast crank in it. I've got a pretty good feeling that it lives a much harder life than what the OP has in mind.

 

This is why Chris was suggesting using the 400 crank in the 455 block.

 

Went with a stock rebuild with the 455 in my 71 Cutlass. Stock 400th and stock posi rear with 3:08 The 455 in my 67 f85 is bored 30 over, bumped up the cam, went with big valves, ported and polished Ca heads. Built 400th and 12 bolt chev rear with 3:08. (Looking to change that).Very happy with that one. Probably do the same as I did on the f85, but go with roller rockers for the convertible. I have a 200 tran I plan on having rebuilt. I have the original posi from the 442 I parted out so I plan on putting in some taller gears to go along with the 200. Thanks for your thoughts guy's. I'll put the 400 and the 400th on the market

 

I like the 425 idea. We have 65 425 in our 67 442 that I think we will be pretty happy with. It is a mild build and make 425 ft lbs of torque at 3200 rpm's! We have the original 400 but needs a major overhaul. Plus the 425 will turn a little more rpm's being that it has a shorter stroke.