I'm running a carburated 7.4 w/2-bolt and Lightning headers. Would an M3 procharger be too much, even at low boost?

I ran a 7.4 with lighting headers and a Procharger for three years at 9 pounds of boost.

The M3 is way overkill for the air demands of that engine, but boost is boost, for all practical purposes the engine does not know if it is an M1 or an M3 as long as the boost pressure is the same. You sure would not have to spin it fast.

2 bolt main should be fine as long as you don't spin high rpms.
Other great stuff will break first

Game, if you want a little added strength, you could put studs in the mains vs bolts. Studs have twice the holding power over bolts. However, if you do go to studs the mains saddles will most likely have to be align honed because of the different torque specs with the studs installed...this is a GOOD machining operation though because everything will be perfect---or at least as close to perfect as you can get it when spinning the crank. A good balance job would be a great idea as well.

Here is my take on this. Buy the M3, you will have to spin it slower to get same boost as M1. Advantages after you get past extra cost up front is

1-spining slower = less heat = motor lives longer.
2- When you build a bigger motor all you will have to do is buy a new pulley instead of a new procharger.

This is the theory I used in buying the M4 instead of the M3. Only time will tell if this goes under wise idea or another lesson learned.

I also subscribe to Jacks theory.

I also have a stage 4, single carb and a 4.5" pulley. I can only go another inch. no jokes please

DAVE

those are my thought in deciding which to get

Sorry for jumpin in here but, for you guys running carbed Procharges, I was woundering who set up your carbs and what the particulars were? Size, (cfm) jets, powervalves etc...?

Thanks in advance,

Bob

Bob

I have the stage 4 with twin holley 450's. factory stock. Motor has not been started yet so I do not know what is right. I was told to put 76 primary, stock PV, 88 secondary. I just got a email from friend who talked to some one who has a 622bbc with same setup with no PV, 63 primary, 84 secondary. Not sure of what carbs exactly. There has been much discussion on this & looks like nothing is the same.