to go i have a 77 highboy,it has a 400m in it now i pull a horse trailer weighing about 10,000#gvw 4 speed manual,i am thinking about turboing it or a 460 with efi if i can find one that will work in my p/u but i can't find any info on the subject at all any where. i was intertaning the idea of turboing the carberated 400m also so i would like to hear both sides of the road.both good and bad either way

 

most turbo applications are custom jobs since a turbo setup requires different plumbimg for each vehicle/engine combo. just do some research on what turbo size you need, and then talk to a fabricator about making up the plumbing and intake.

 

A smaller turbo compressor will spool up faster and allow the engine to build torque at a lower RPM (good for towing). But, as mentioned above, you'll need to have some custom plumbing done to make it work and that'll cost some extra $$.
With the 460.....if you can get a complete engine harness and computer (for a manual tranny) with the motor then you should be in good shape.
If you go with a 460 EFI and put a turbo on it, then you wouldn't have to decide which way to go.

 

ya i didn't say that but i was thinking it i am leaning that way vey hard