I know this has been asked a million times and I used the search with no luck. Wasn't there a post last year of exactly what was needed to convert a 72 elky from a 350 to a 454?
Some of the things I was wondering are:
motor mounts need to be changed, I am assuming. but, the frame mounts should be fine.
If it came with a 350, will I need to change the fuel lines (it'll be a mild street 454).
I heard that if it WAS a sb car with air, if I cam going to a BB with no air, my radiator should be fine for the time being, right?
I remember reading all of this before but I can't find the thread.

i am watching this post myself as i am planning almost the same thing myself (only 406:454). one thing i noticed was that the spring part numbers for a small block with air are the same as a big block w/o air. that is good news on the radiator, i have a newer 3 core but figured i might have to go 4 core. if that isnt essential right away that would be a good thing. hadnt thought about the fuel line, i assumed that would be in the same place. maybe not. i wonder if any of the detail things like starters, flex plates, alternators, power steering pumps will exchange. i am assuming they dont. always plan for worst case and if you find some gravy in there then great.

Flex plate won't work, need brackets for the alternator, power steering, I used the 3 row a/c radiator and shroud that were used with the 350. The starter will work. I'm using the stock 3/8" fuel line.

The fuel line on a 350 is larger than the 6 cylinder, right? I know from another post you need to change lines if you have a 6.

I'm in the middle of a changout in a 72 ss.
The parts you'll need are:
-coil springs
-brackets: alternator, ps, ac
-pulleys
-i believe flexplate. I have an extra one. I did a 454 HO to a 4 speed so i didn't use it.
-Oil pan if it is a crate motor.
-The motor mounts are the same
-accelerator cable
-trans? going from turbo 350-400?
-short fan shroud
-possibly new ps lines for bb

If I think of anything else I will post.

A fat wallet also helps! smile.gif

I've been conteplating trading my 388ci for my buddy's 454. I'll keep an eye on this post as well :D I know one thing for sure...I'm gonna need new headers.....again!!!! graemlins/clonk.gif

Ahh, fan shroud, didn't think of that.
I just got a new flex plate.
My 454 came with most of the brackets.
I got a turbo 400 thrown in with the engine.
Pullies I'll be getting new anyway.

What I'm doing is trying to put together a complete BBC and tranny assembly. I want to just pull out the old driveline and drop in a new one. So, I'll be replacing pullies, water pump, carb, etc. anyway. I was thinking of reusing my old HEI distributor. But, even that I'd like to replace.

I was mainly contemplating things like fuel line, radiator, springs, fan shroud, etc.

Yeah headers are pretty obvious. I'm glad I only bought the $79 summit cheapies for my SB. I'll be going ceramic coated this time.

As far as the springs, I read somewhere the front end would drop 1/2 inch. If that's all it'll drop, I just may leave the old springs in. Anyone know if 1/2 inch is right?