Streetmaster 390 versus Performer RPM

[dustman_stx]

I thought I'd share my experiences( I don't think I posted this yet) between these 2 intakes. I built a 390, bored .030 over, forged rods and pistons, 10.1:1 CR, full roller with comp cams 292S cam, headers, Mighty Demon 750, MSD ignition, Mallory Unilite. I am running stock C8AE-H heads that have been ported and polished, CJ size valves installed, etc. For the record, no tuning has been done except to set the timing. Plan is to get it tuned on the chassis dyno as soon as I get the funds. To make a long story short, these 2 intakes performed very similarly for me. I have a really aggressive cam. The dual plane design of the RPM did make the engine run smoother at a slightly lower RPM. With the Streetmaster, you typically had to get to around 3200 RPM for the engine to run smoothly, whereas the RPM starts to smooth out around 2700. Not a big deal, but a little more town-friendly with the RPM. Just by the seat-of-the-pants feel, I think the RPM produces a slight amount more power in the 2800-3500 range. I started with the Streetmaster, and changed to the RPM. ( I had read Jay Brown's review on the Ford FE forum, but I'm the skeptical type and had to find out for myself.) After making the switch, I won't go through the hassle of changing back, but I definitely wouldn spend the extra money for the RPM if I had it to do over. Also, I was thinking about running a 100 shot at some point, and the single plane Streetmaster would be a much better candidate for that. I guess my point is that unless you are going all out race and really need your FE to breathe up top with a big single plane, either one of these intakes will suffice.

[ximy]

I was told not to use the streemaster on an FE but my experience is similar to yours.. for me... the more the cubes with the streetmaster, the better... the streemaster made good torque from idle to midrange... with a 292/540 bumpstick (LOW RISER heads). The 428 loves it and doesn't operate much past 5500 anyway.

I also used it in a 440 cube C6ME block and ported to match heads... a terror on the street.