Newb with lots of questions

[skinnysfd]

posted in the wrong section earlier so here it is:
Alright guys heres the deal... I have a 1970 gmc pictured below and want to set it up for drag raceing 1/4 mile. so far my best time has been 14.05 and i know i have around 3:11 or so gearing in the rear end. it also a one wheel wonder. i have the motor built as well as a built tranny in it. the motor has been dyno'd at 400-450 hp motor alone . now i want to run in the low to mid 11's for starters and go from there. i have a 100 shot nitrous avaliable and am running only a 2200 stall convertor right now. so im thinking going with a 3200 stall ( because motors dyno sheet showed 3500-6200 is the power range) and putting in a different rear end with different gearing. so my question is ... Am i on the right track in this thinking? If so whats the best gearing for these trucks and what rearend? ford 9", chevy 12 bolt??? also wondering if i should go 4:11 or 4:55 whats yalls experience and any other advice is welcome and needed. Also going to be putting fuel tank in the bed as well and getting it out of the cab. was also thinking a 2" front drop and 4" rear drop???

[JointTech]

wow im surprised this didnt get any bites. who did you piss off around here lol
nice truck. Heres a bump for you.

[skinnysfd]

hahaha idk must have pissed off someone lol but i did post it in another section and got quitea few replies on that one . thanks though

[JointTech]

i ws just looking at the truck at first and didnt notice that burnout was in the middle of traffic. LOL was it a parade or something. i see people on the side of the road.

[skinnysfd]

it was a cruise night we do every year here and i did get a couple tickets that night haha cause apparently i was the only one smoking out intersections lol but the crowd loved it so i had to keep going

[Marv D]

Well as always I have to start with a question. What's up with:

the motor has been dyno'd at 400-450 hp motor

If it was dyno'd,, where was the torque peak, and after you hosed it where was torque and HP peak and exactl what RPM

What does it weigh in race trim?

You obviously will have to optimize the suspension, gear, and tire for traction. What was your 60'

What elevation is yor track? do you know an average density altitude you have when it's race season there?

So from there,, and making a bunch of assumptions (like she is probably around 3800-4200 pounds? you are going to need well north of 600 REAL HP to get to 11.0's
And what happens in teh first 100' of the track is compounded all through the run. You will need either a BUTTLOAD more power to make up for a poor reacting chassis, or get the thing to 60' in the mid 1 second zone (1.50 and probably no more than 1.65,, 1.4's would make up for some of the pork your trying to push down the track)

Oh and last question (for now) umm this 400-450 HP motor., what the heck is it!!! small block, big block, LS.?????

[Bad70sbchevy]

As far as the rear end goes, mine makes around 425hp so its in your ballpark and I've been running the stock 12-bolt rear end with no problems what so ever. Both the 12 bolt and the 9" will get the job done, especially for that power level. As far as gearing goes, it depends a lot on wheel size, tranny, power numbers, etc... Ideally you want to run enough gearing just to the point of hitting the end of the power curve by the time you cross the stripe. 4:11s are a good place to start IMO.

[GASoline71]

I was wondering about the dyno run too. A dyno run will tell you EXACTLY what the engine did. Not a guesstimate of 400-450 hp. Plus TQ is where it's at on dynos... so we await for the peak TQ figure from the dyno.

Gary