i recently bought a 1977 f250 highboy with a 400 in it. it has a holley 4 barrel and the guy i bought it from thinks it has 2 bad valves which is possibly the reason it wont idle. is this a common problem with this engine and what other kinds of common problems does this engine have?

 

Welcome to FTE!

Burned valves are no more common with the 400 than they are with any other engine. The most common problem is low oil pressure but they will run for a long time with low oil pressure.

 

I would check for vacuum leaks first then go from there.

 

is there any type of heads you would recomend possibly out of a 351c

 

clev. heads are the same as the 400 heads unless u get assui heads. they have a higher compression ratio and are a closed chamber design i second the vacume leak theory

 

this thread should be called 400 wont die.