My combo is a 383 xe288hr cam ,411 rear gear,th400 trans with a 4200 stall, 150 shot ,drag radials , 2/5 true duals through x pipe and 40 series flownasters and I just finished all my suspension mods and I'm wondering if the car would be winding out on the top end because of the rear gear and or stall combo any suggestions or comments on 1/4 mile guesses or combo would be appreciated

 

What heads, what tire diameter? What intake manifold?

 

Without even knowing the rest of your combo I think it will be done well before the end of the quarter especially with a shot. This is based on my car with street tires and no spray.

Mark.

 

275/50r15 tires street slicks, dual plane edelbroch rpm perfomer intake.my nitrous is currently 100 shot but my kit can go up to 175

 

Sportsman2 heads ported and polished

 

Any ideas on port volume and flow after the portwork? Also what compression? Lastly how much does car weigh?

If the springs match the cam well and no valvefloat, and if heads are decently ported, i can see 450-475 hp which should be good for high 11's at 115 mph in a 3400 lb car. Those tires being 26" tall, 4.11's are a tad high considering 6500 rpm shift with that cam. Cant really say what the power is without data on the heads. If mild clean up only it could be only 425-440 hp and run lower 12's. 4.11's wont be as bad then.

Now nitrous will add another 6-10 mph to your trap speed assuming 100-150 shot well tuned. Traps in the low 120's needs more like 3.42-3.73's or you will run out of gear with 26" tire. Probably 3.73's or step up to a 275/60 tire.

If heads are reallly good and flow upwards of 280cfm could make closer to 500 hp and trap 118 all motor and closer to 128-130 mph on spray. Alittle less gear wouldnt hurt, 3.42's with a 26" is what i used with a 6600 rpm shift. 3.73 may have been a touch better but difference would be negligible imo. Also less gear may help launch by keeping torque down allowing traction

 

That 4200 is a lot of stall for anything more than a 100 shot with your combo. I have a 4200 in my Impala, optimized for NA. It flashes to 5800 with the 100 shot.
In your car, I'd run 3.73's as a compromise between NA and nitrous. If the converter is any good/efficient at all, assume about a 7% slip at 6500 rpm, and it will be at 125 mph with 26" tires and the 3.73's.
For optimizing on nitrous, I'd run 3.42's. Like Orr said, it will help your launch with that converter, and will give you a prayer of hooking up the 150 out of the hole.

 

Im leaning toward just going with a taller tire in the back but that will probably lead to some rubbing with the taller tire. Any one have any issues with the 275/60/15 Lip rolling required?

 

Thanks for all the info!!!

 

28" tire is a good idea. If backspacing is right should fit fine. Minor work to front well area. I have a 305/35/19 which is 27.5" and 12" wide. Fits fine with alot of hammering front well. 275/60 should be easy

 

Id run it as is just to see what its doing get a feel for the car sort out chassis etc. Few runs youll know what you want to do with it.

 

Yeah 275/60/15's are the way to go with spray and it still will be screaming through the traps... 275/50/15 for a N/A combo.

Goodluck!