Help me optimize my build

Well, where to start. I guess it'll be with a little background on my build. My project is an 86 Mazda RX7 that I've dumped the crappy old rotary for a nice mild 360 Magnum. The reason for this is simple, I want to go drag racing! Why? Well, I already had the engine (built for another project that was abandoned), and the car was sitting in a friend's garage with a blown rotary. I looked under the hood and thought to myself "Wow, look at all that room!!! I bet that 360 will fit in there!!!". So we worked out a deal and I towed it home. Project Mopar RX7 began.

Phase one of the project is complete and the car is running and driving under Mopar power, so now to phase two, upgrade. The current combo is as follows:

-360 Magnum, bone stock rotating assembly
-Stock heads and valve train, except for upgraded valve springs.
-Comp Cams hyd roller: 216/224 @.050, .506/.506, 114 (Comp spec'd it for a boosted application, my abandoned project)
-Edelbrock Airgap intake
-Carter AFB 625
-Stock ignition from a 85 Ramcharger
-1 5/8" block hugger headers (not optimal, I know, but they're the only ones that fit)
-2 1/2" dual exhaust with x-pipe

-Bone stock lock-up 904 and converter

-Stock Mazda Turbo II limited-slip rear, 4.10 ratio. Yes, it "should" be strong enough.

-Car weight is 2890 lbs with a 1/4 tank of fuel and w/o me in it. 52/48% weigh distribution, but I'm still trying to move weight around to get it back to 50/50.




Here's what I've started work on already.

-Tires: M/T ET Street Radials, 255/60-15

-Transmission: Non Lock-up 904 being built with TF-2 shift kit, low first gear, and whatever else my builder is doing to it. Should be finished soon. I don't have a converter on the way since I can't call for a recommendation until I get everything else sorted out. Feel free to make a suggestion if you like.


Ok, so here's a few things I'd like to know.

1.) Cam: I don't think it's the right one for the car, and I'm thinking you all will agree. I've been shopping around for a new roller cam but they seem to have more lift than my stock heads will handle without removing them and cutting down the guides. I'm not trying to cheap out here, but if my heads don't flow well over .500 lift, why go through the expense of machining the heads and possibly having to upgrade my valve springs again when it won't do me any good? So that led me to this. My idea is to contact Comp and ask them to grind a cam similar to, for example, their XE274H cam, but as a roller and with about the same lift as my current cam (.506/.506) so it can be easily swapped without modifying my heads. So the specs would be a roller with 230/236 @ .050, .504/.506 lift, 110 LSA. I'm not sure if the XE274 is the right choice, I was just using that as an example. If a roller ground similar to a XE268 cam would be optimal, great, no problem. What are your thoughts?

2.) Carburetor: I've gotten several different opinions on this(mostly from Chevy or Ford guys), but some input from guys who race a Mopar would be very helpful. I've searched around and I seem to fall right in the middle between a 650dp or 750vs with my gear ratio and weight. A 3310 Holley would be a nice inexpensive choice, but if a dp would be best, then so be it. I'd be happy to answer any more questions about this subject so feel free to ask. I don't particularly care about gas mileage, this is my toy, not my daily driver.



If there is anything else that you need from me, please feel free to ask. I tried to be as specific as possible. Thank you for your time.