this is just one persons opionion...

I would not port the manifolds. The casting is somewhat thick, but the consistency throught out the manifold is horrible - thinner in spots than others.
Plus they are horrible for cracking under stress, specially the PASS side.

I also wonder if all th effort to port them would really yeild all that much performance, as opposed to a great set of headers?

My 2 cents ....

Bill

Got me a NEW Project
1970 GTX 440+6, 4 spd, 4.10 Dana and N96 FE5 (top/bottom) and black bucket interior.
Original transmission and Dana - Engine is a service replacement block.

Body has all stamped #s + VIN/TRIM tag and door sticker. Been hunting like all hell to find the Build Sheet.

garage find, only had 41,850 miles on ODO.