Slant stumbling on acceleration

Why not do a wet and dry compression test and see what condition your cylinders are in? Let's make sure that there isn't a low cylinder or two first, then build up from there.

Are you running points or electronic ignition? Details...

A stumble can be caused by many things. Let's make sure that your base "core" is good, especially if you are going to change the intake soon...


What are your timing settings? Initial advance? Total advance?

Also look at the spark plugs and see if they can tell anything... Rich... Lean....