Thread: 4 bbl or 6 pack

Tweet

I am building a stroked 340. I will be using a hughes 3742al cam, 1.6 rockers, ported x heads, 10 to 1. This will be in a 72 dart with a 904 TF, 3.23 8 3/4 rear.
My questions is will a mopar performance 6 pack be a better choice for streetability and performance or will the 750 mighty demon and performer rpm be a better choice.

What's your final displacement, and will this be primarily street driven car? A cam with 237/242 duration at 0.050, 0.584/o.592 lift, and an effective RPM range of 2500-5900 seems awfully radical for the street - especially with 3.23 gears. It also seems like a 750 CFM MD is an extremely large carb for that application. You'll need a converter with a stall of about 3000 RPM. It's just me, but I'm guessing that this combo with either the 3x2 or the 4bbl is going to be a real pain to drive on the street, and will have no grunt on the low end. You'll have to get it up on the cam to make it go.

- but that's just me . . .

I agree with HR, you are building a high RPM engine and asking it to work at low revs. Either cut back on cam and carb or go for steep rear gears and lighten the Dart drastically.