I am swapping a 71 455 into my 70 skylark, until now a 350. How difficult is the conversion? will I need to cut the drive shaft? are there detents to show where to mount the new frame mounts? Are there any mistakes to avoid? I'don't have my springs yet, should I wait until they arrive, or do them after the fact?

The tranny and driveshaft do not have to move, they bolt right up to the engine where they are. Nice, eh?

Some frames were already drilled for the frame brackets, some require a single hole drilled. Just line up the bracket and drill the hole where (if) you need to.

-Bob Cunningham

Bob-
Thanks for the reply. I forgot to mention that I am also upgrading to the TH400 trans with the big block swap. Does that make a difference regarding the length of the drive shaft? I'll tell you what is nice though. I was able to remove my entire front end, radiator core support and all in about an hour. If I had some sort of a dolly system, I could probably roll the transmission and engine straight onto the frame mounts without even using an engine lift.

-Joe

I don't know what tranny is in there, but it's probably that you'll have to change the driveshaft length. You will probably need a new front yoke also.

-Bob Cunningham

will you need to change out the front springs also? will the small block springs be ok with the extra weight?

It's not a bad idea, but might not be necessary. The 455 is the lighest of the big blocks (about the same as a small-block chevy), so you might not see much of a difference.

I would wait and see how you like it first.

-Bob C.