ok guys im doing a tpi to carb swap on my 350, I'm gonna run the performer air gap intake, im still debating on the heads, and will be running the xr282 cam from comp cams. my question is which distributor to run. an HEI would do i believe but a vacuum advance or mechanical advance is the one im not sure about?! which one would be good for that cam? and i want to go with a 750 cfm but not sure what brand. ive heard demon carbs are pretty good but this is my i need u guys recommendations!! thanks in advance guys

Hei will be fine. Get one with vacuum and mechanical advance for street. For racing vacuum advance is not needed. Make sure to connect the vac adv to the correct port on the carb. I prefer holley carbs. Demon, proform, bg, are all based on a holley.

Thanks for the reply. Ive seen some people using the street fire msd disributor , do u think that would be ok for my set up?

People that have properly working Demons love them. However, when problems do arise with Demons, parts are much harder to come by opposed to a Holley carb. Summit discontinued their contract with Barry Grant because (don't quote me) 2 out of 10 were returned with some sort of defect. I read that somewhere I cant guarantee the accuracy of the numbers though. As for the distributor, I used to use the street fire. I had no issue with the distributor itself.

GM performance HEI...has the good melonized gear for use with a roller cam and the mechanical curve is better. As for a carb, any "double pumper" type should be good. A 650 might be sufficient, but a 750 would be okay too. I like my 750 Mighty Demon with Annular boosters.

The GM HEI coil is one of the best out there for spark energy. This has been my experience and what a VP from MSD had told me as well. Weak points would be the button located under the coil that goes to the rotor and the control module. Both are cheap upgrades compared to a new distributor. If you are dead set on new, my first choice is MSD. I've raced with Mallory and MSD and have owned an Accel and out of the the the MSD had the better build quality and had withstood the beating for many years of drag racing where the Mallory Uni-lite did not.

That being said I have a Mallory distributor in my 86 and it is great for street driving and the occasional track run (I'm not hitting 7K racing every weekend like our race car did). I had to buy a new distributor and I got one heck of a deal on this Mallory unit that I could not pass up.

With carb selection, unless you have some good flowing heads, cam and exhaust, the 750 is going to be too big. If you are mostly cruising and moderate driving I'd go with the Edelbrock. If this is for street/strip application I'd go with a Holley type carb with mechanical secondaries. I would not go with a Holley vacuum secondary unless you know how to tune a carb for best performance.

Thanks for all the answers guys! So u think the msd street fire would be my best one or the gm one. I like the price on the street fire and will probably end up with that. How good are the double pumpers? Or what type of holley carb would be good?

I personally like the proform carb. I do not get why people think bigger is better? I suggest you use the cfm formula to determin what cfm is best for your application. If you are street using this car 650 is MORE than enough. over carbing will lead to other problems. Good luck.

Check and see what gear is on the street fire and if it is compatible with the cam gear. I am betting it is not.

What type of gear is it suppose to have? And why would it need a certain type of gear?

There are several varieties of gears that come on cams and on distributors. Not all of them play well togehter. "Generally", the roller cams need a melonized gear or a composite gear or a bronze gear on the distributor. Of those 3 choices, the melonized is the best for long term durability. It has been a while since I wasted money on MSD, but the gears used to be plain steel and those will not last long on a typical roller cam. Maybe MSD stepped up and uses better gears now, but I doubt it.

Thats some good info, ill look into that thanks

The steel gear that comes stock with most aftermarket distributors are meant for flat tappet hydraulic cams. For other applications you must buy the proper gear and swap the gear out on the distributor. Just because you buy one brand distributor doesn't mean you have to buy their gear. Comp Cams also offers gears that will work also, See Here--> http://www.summitracing.com/search/d...rand/comp-cams

With that being said im going to order the msdstreet fire distributor, cant go wrong with the price and if i need to swap the cam gear ill just order it not to much of a biggy. Thanks for the help guys. Ill will be ordering a carb next once i decide which one to go with

The point of my post was, if you are paying a premium for MSD stuff, they should step up and provide a good gear that is compatible with more than a flat tappet cam Like the melonized gear). MSD will happily sell you the right gear for their distributer and your cam (or some other companies gear), but that is even more money. You should buy the GM Performance HEI. It is the better deal.

It's the same with Accel and Mallory. There isn't a one gear fits all out there. If they installed the softer material gears on the dist. then everyone would be complaining about the longevity of the gears.

Bought a used Demon for $300. Found throttle shaft leaks. Many calls to tech support they assured me there was no way a carb could leak there. Bought another Demon. Vacuum ports weren't even drilled all the way in the base plate. I returned it and bought a Pro-Systems (holley). I haven't drove the car yet but so far Pro-Systems seems to be much better idling and hot restarts than the leaking Demon. I don't plan on buying another Demon ever.

Ok then demon is out of the picture. Ive heard holleys are very delicate. Why is that?

Have Pro Systems build a Holley. It'll be a 780cfm and SPOT on. Worth every penny.

I ran an MSD billet with timing locked at 35 degrees but I banned MSD from my garage because of their boxes... Mallory 685 Digital all the way and I would try a Mallory dist or even a Proform.. Had good lock with one.

Goodluck!

I found most of the problems with the newer MSD boxes is due to the RoHS compliant solder. The no-lead solder has a tendency to pull away from component leads leading to intermittent or the unit not operating at all. Manufactures are being forced to use no lead tinned devices because that is the only thing being supplied by the part manufactures. Not excusing the quality of MSD ignition boxes but the quality of their distributors is hard to top.

I just finished repairing my MSD 6-AL and it failed due to bad solder adhesion. I removed a lot of the old solder on a lot of the joints and replaced it with Sn63Pb37 rosen core solder. For any ignition module vibration mounts are a must and the unit should be installed where it's not exposed to extreme heat and not in an area where heat is being trapped and there is no air flow.

I'm seeing more and more problems with RoHS compliant devices over the years. There is a reason NASA will not allow lead free soldering on their devices

Wow, no Qjet love at all here. I'd recommend a Qjet over a Holley or Edelbrock any day, they just take abit more to get set up right.

I will look into those qjets , my msd will be here tomorrow. I couldnt go wrong with the price so i went for it