Pontiac 301 to 400 conversion question

[buzz77]

Ive been getting conflicting information so anyone who has swapped out a 301 for a 400/455 chime in.

Can the pulleys from a 301 be used on the 400. How about the alternator and p/s brackets?

And what brackets did you use for ac/compressor? Thanks

 

[82GPLJ455]

Im not sure if theyll work but everything off the 301will bolt onto the 400.the A/C brackets will work.

 

[G-Body_Vet]

I had 301 stuff and 455 stuff. After a few years of project hiatus I lost track of which was which. I ended up buying this kit and it worked out for me.
http://www.ebay.com/itm/Pontiac-Power-Steering-Alternator-Bracket-Billet-Aluminum-350-400-428-455-/111551274865?fits=Makeontiac&hash=item19f8f95f71&vxp=mtr

I think I had to drill out one of the alternator bracket holes and a bolt or 2 weren't long enough, but I used stainless anyway. If you care to see pics I can take some later on.

 

[buzz77]

definately would like to see pics of the set up. The A/C set up is concerning me. The compressors were larger back then, and dont know if they will line up. Also some confusion on whether the crank pulley for the 301 is the same as the 71-79 400 pulley

 

[G-Body_Vet]

It was my plan to use the 301 ac bracket too due to the R4 compressor. I'm leaning towards an aftermarket compressor now when the time comes, and IIRC there's a conversion bracket for that too. I know that probably doesn't help you much but here's my current setup anyway

 

[buzz77]

Wow your set up looks amazing. Is the alternator also bolted to the head? Maybe a problem for am as im using a pre-1970 head.

 

[G-Body_Vet]

Thanks I appreciate it. In the last pic you can see where it bolts to the head. It's that long spacer just above the power steering pump. The kit I have could use some engineering improvements but it works and not as expensive as a complete serpentine setup would cost.

 

[buzz77]

Can anything be used from the 301? The 400 block Im using still needs the oil filter housing and fuel pump. Can those be swapped or will I need 400 compatible parts.

 

[G-Body_Vet]

I'm not 100% sure, but from what I remember, the main things that won't interchange are the intake and exhaust manifolds.

 

[82GPLJ455]

The fuel pump will swap.the oil filter adapter should swap.youll need to use the 301 block mounts.wiring harness will work with no mods.