intake choice

[427Fastback]

My 427 is mild mannered.I have edelbrock heads (2.19.1.7 valves) Comp 270s cam,9.5-1 comp and FPA headers.There is more stuff but that's the basics..Car (68 Fastback) is street driven 100% with 3.5 gears.

Question is...I have Jays lower intake and I am curious as to what would be the better choice for a top manifold..The 351 torker or the 351 air gap...The air gap ports are much smaller than the torker

I already have the torker and I did read Jays book...I know nothing about the 351C airgap tho..

Cory

[jayb]

I think I would go with the Performer RPM air gap, Cory.  It is going to be way ahead of the Torker up to 4500 RPM or so.  I just had to make the same choice with my 428CJ, which is about a 440 HP engine, and I went with the air gap manifold.  I did open up the ports on the manifold somewhat to better match the intake adapter, but based on my dyno tests that manifold performed really well, even without the port match.

[427Fastback]

The air gap has been my choice for a while now and I find it interesting that you also went that route...
Did you have to open the ports much ??You don't have any pics of the work or of it all assembled do you..??
I used to run a C7-F intake and even with the CJ exhaust manifold it would rev cleanly to 6400 rpm.I don't imagine this set up will struggle with that.....Cory

[jayb]

I don't have any pictures, unfortunately, should've taken some I guess.  I left the intake adapter port the same size on the intake side, but I did smooth the CNC marks with a cartridge roll.  I also opened up the intake adapter port on the head side to match the sides and roof of the 428CJ port.  That port was very close already, so not much needed to be done there. Then I opened up the ports on the 351C intake to match the intake adapter.  Just a couple hour job to get it all done.  Its easy with the adapter because you can plop it onto the engine and see where the ports need to be shaved to match the head ports.  Then you can take the adapter off the engine, bolt the intake onto the adapter, and look up through the ports in the adapter and scribe the intake so that it will match up to the adapter ports.

[427Fastback]

That's true.The manifold has smaller ports than the adaptor so its easy to see and scribe..My heads are still on the bench so fitting things up is pretty easy...
Thanks

[bn69stang]

Not to steal the thread , but Jay what rear gear are you gonna run ? , thanks Bud..

[jayb]

I had an N case 4.11 Detroit locker sitting on the shelf, so I put that in the car.  Should work pretty well with the overdrive gears.

[bn69stang]

Thanks Jay , i guess i took smaller steps to go from 3.50 s to 3.89 s , but while rear end is out i will be upgrading to rear disc brakes .. Bud

[FElony]

Is the Cleveland Air Gap that much better than the FE RPM?

[Joe-JDC]

I just bought a new FE Performer RPM for myself, and I flowed it as it came out of the box.  The average flow for the manifold was 298 cfm, with best port 317 cfm, and worst 278 cfm.  I don't know if the latest version is different, but I have checked several in the past that averaged well over 300 cfm, so something has changed.  I haven't had a chance to flow the cleveland RPM, so I can't give any figures on them.  Joe-JDC

[jayb]

Is the Cleveland Air Gap that much better than the FE RPM?

In a word, no, at least on my intake adapter.  It made nearly the same power on my 428CJ as the normal FE Performer RPM.  But, you can pull it off and throw on the tunnel ram in 15 minutes 

[FElony]

Is the Cleveland Air Gap that much better than the FE RPM?

In a word, no, at least on my intake adapter.  It made nearly the same power on my 428CJ as the normal FE Performer RPM.  But, you can pull it off and throw on the tunnel ram in 15 minutes 

I had planned to put my tunnel ram on a J-Dapt, but it seems the availability of said piece is apparently stalled or sold out. I snoozeth, I loozeth. I suppose I can actually put it on a Cleveland.

[FElony]

I just bought a new FE Performer RPM for myself, and I flowed it as it came out of the box.  The average flow for the manifold was 298 cfm, with best port 317 cfm, and worst 278 cfm.  I don't know if the latest version is different, but I have checked several in the past that averaged well over 300 cfm, so something has changed.  I haven't had a chance to flow the cleveland RPM, so I can't give any figures on them.  Joe-JDC

Well, that's bizarre. Have you fiddled with the Edelbrock 8V Air Gap?

[Nightmist66]

I suppose I can actually put it on a Cleveland.

Where would the fun be in that? 

[Joe-JDC]

I just bought a new FE Performer RPM for myself, and I flowed it as it came out of the box.  The average flow for the manifold was 298 cfm, with best port 317 cfm, and worst 278 cfm.  I don't know if the latest version is different, but I have checked several in the past that averaged well over 300 cfm, so something has changed.  I haven't had a chance to flow the cleveland RPM, so I can't give any figures on them.  Joe-JDC

Well, that's bizarre. Have you fiddled with the Edelbrock 8V Air Gap?

Yes, I have ported the FE 8V RPM Air Gap, and it works VERY well after porting.  I have been keeping my eyes open for one for myself, but they seem to be scarce.  One member put one on his roadster, and broke the transmission from the torque produced.   The flow on #8 runner is not the greatest as cast, but with work they can be balanced very well.   I would like to compare one that has been well ported to the BT 8V that has similar work.   Joe-JDC