Which intake matches up to P.I. heads ?

A buddy of mine has a 71 ltd .Our plans are 460 c6 3.00 3.25 rear .This will have a mild hyd cam 9.5 compression headers tight convertor and d2 429 pi heads .Right now no plans for head porting .We plan on some dual plane intake rpm limit 5000-5500 .I am wondering about port matchup .I am aware something like a performer would have smaller ports than the pi heads we have .Is it worthwhile to make the intake match the head size ? or is it not a big deal? And on the other hand what about using something with cj sized ports ? I believe my buddy has a Blue Thunder dual plane with cj ports .That Blue Thunder has a big plenum I believe .I took it off my comet drag car and installed a trickflow dualplane cj intake (now discontinued )and the trick flow was two tenths faster .My buddy bought the heads off craigslist for $900 ready to go

manofmerc wrote:A buddy of mine has a 71 ltd .Our plans are 460 c6 3.00 3.25 rear .This will have a mild hyd cam 9.5 compression headers tight convertor and d2 429 pi heads .Right now no plans for head porting .We plan on some dual plane intake rpm limit 5000-5500 .I am wondering about port matchup .I am aware something like a performer would have smaller ports than the pi heads we have .Is it worthwhile to make the intake match the head size ? or is it not a big deal? And on the other hand what about using something with cj sized ports ? I believe my buddy has a Blue Thunder dual plane with cj ports .That Blue Thunder has a big plenum I believe .I took it off my comet drag car and installed a trickflow dualplane cj intake (now discontinued )and the trick flow was two tenths faster .My buddy bought the heads off craigslist for $900 ready to go

A P.I. head has an intake port flange only SLIGHTLY larger than a regular passenger car port; not near as large as the port on a CJ head. (The 2.200" intake valve size today is a derivative from the P.I. heads).
The exhaust flange is centered in height the same as a CJ flange.

Use an intake manifold meant for a REGULAR port flange unless you have "port matching" the head in mind..

Really that is good news to me I havent used any P.I. heads in a while .Most likely we will go with an edelbrock performer .Thanks Mr. Malik .Doug

manofmerc wrote:A buddy of mine has a 71 ltd .Our plans are 460 c6 3.00 3.25 rear .This will have a mild hyd cam 9.5 compression headers tight convertor and d2 429 pi heads .Right now no plans for head porting .We plan on some dual plane intake rpm limit 5000-5500 .I am wondering about port matchup .I am aware something like a performer would have smaller ports than the pi heads we have .Is it worthwhile to make the intake match the head size ? or is it not a big deal? And on the other hand what about using something with cj sized ports ? I believe my buddy has a Blue Thunder dual plane with cj ports .That Blue Thunder has a big plenum I believe .I took it off my comet drag car and installed a trickflow dualplane cj intake (now discontinued )and the trick flow was two tenths faster .My buddy bought the heads off craigslist for $900 ready to go

rmcomprandy wrote:

Use an intake manifold meant for a REGULAR port flange unless you have "port matching" the head in mind..

Could your plan consider a C4? As Randy mentioned, intake manifold and/or cylinder head ports alignment would be an asset.

Dave.

This isnt to be a street racer just something my buddy wants to do to his ltd .It has a 429 2v with c6 .We will probably just build his c6 .And install a mild convertor .Really not a bad idea though .One thing for sure if we did have a c4 in it lots of room . Thanks for your input .Doug

manofmerc wrote:This isnt to be a street racer just something my buddy wants to do to his ltd .It has a 429 2v with c6 .We will probably just build his c6 .And install a mild convertor .Really not a bad idea though .One thing for sure if we did have a c4 in it lots of room . Thanks for your input .Doug

..... your car would be noticeably quicker and more efficient!

Dave.