Originally Posted by carringb
The stock cast exhaust manifolds are prone to cracking. Banks makes a really nice set of headers for the 460, which won't leak, and will add a lot more power if you install the complete PowerPack set.
x2 on the manifolds. The later ones (My '88 F350 w/460cu in for instance) has the improved cast STEEL
manifolds, which are far superior to the crack-prone cast iron ones. But the problem with the later ones is getting them machined flat during the course of an engine rebuild is expensive, the steel manifolds are tough as nails compared to cast iron. Also, the manifold bolt threads seize in the heads, break off when you try to remove them, the broke-off threaded sections are all but impossible to extract yourself (ask me how I know). When you reassemble, you need to use brand new Ford factory titanium exhaust manifold bolts from Ford, which are a little
'spendy', but not too bad for titanium hardware, maybe $8/bolt if I remember right.
The other trick with the 1980's 460's, that supposedly gains a little more mpg, and (as I'm told) noticeably more torque, is to advance the cam (retarded by the factory to help with emissions, but turned this mountain motor into an ant hill) by means of either A) using a different timing chain set, B) degreeing in the cam yourself and drilling a new dowel hole, or C) just using a new low-to-mid-rpm range performance Engle camshaft and matching lifters. I'm told it will still pass California Emissions testing (non-dyno). BTW, I have said new Engle cam and lifters that I never got around to installing, for sale cheap, if you need them, as my 1988 F350 is about to get a new home.