Right now i have a 360 in the 81 d-350 would a 440 or a 383 fit (have both with tranny) in the engine bay with out much trouble.

 

You need:

Engine
Big block motor mounts (http://www.bouchillonperformance.com/BPEtruckKit.asp)
Big block tranny
Bigger radiator (should have if you live in a hot area)
Exhaust
Might need a smaller brake booster (I used one for a late 80's Dodge Daytona)
Custom fit headers (http://www.bouchillonperformance.com...rManifolds.asp)
Rear sump oil pan and pickup (http://store.440source.com/Oil-Pan-R...info/111-1000/)

 

the 440 will be a tighter fit than the 383. Cause the 440 is a "RB" (raised block) which is several inches wider than the 383.

 

Even with a 440 in there I have tons of room. Only thing was the smaller booster.

 

NICE, I LIKE!! I have a small booster off one of my trucks , if anybody is interested. It worked fine, but the one stud that holds the master broke. i'm sure it can be fixed.