top speed of souped truck

[jveik]

im restoring an old 73 chevy pickup and i want to know the neighborhood of what the quarter mile time might be. it weighs about 4000 pounds i would assume, due to the lighter replacement crappy panels lol. it is 2 wheel drive, has a 12 bolt posi rearend, but i dont know what gearing for sure... it used to be able to hit 60 no problem in first gear before i took it all apart. im throwing the th400 tranny back in there with a transpak shift kit and im dropping in a 383 rated at 450 horsepower at about 5800rpm and 500lb/ft of torque at about 4000 rpm. im also going to be running a torque converter that has about a 2000rpm stall speed as advertised, though i would assume the torque of the engine would raise that speed a little bit lol...

any ideas of a ballpark figure or should i just wait till i get it built and then run it on a local drag strip?

[GreyGoose006]

i'd guess around mid to low 13's if you can get the rear to hook up.
with all that torque, you may look at getting drag tires on the rear if you plan on seriously drag racing it.

[jveik]

can i get decently wide tires on the stock rims (sweet looking ralley's) or would i have to invest in some cragar rims to get that done? i think i will try bigger tires in the back to help that damn traction, i guess the posi will help me a lot too... i didnt even know it had posi till i did a burnout and my buddy behind me said it was spinnin em both lol...

[GreyGoose006]

what is the width on your rims.
you can really only safely go with tires that are 2-2.5 inches wider than your rims. I wouldnt go more than this but thats not saying it isnt possible.

get some 9 inch rims and 12 inch tires and you will be golden.
(yes, i know 12-9=3, but with wider rims, it dosent matter as much)

[534BC]

Your top-speed will be determined by the gearing since you have already established the hp at an rpm of 450 and 5800. The weight and wind resistance is also a constant since you list 4000 and it's a truck.

Rear tire diameter and rear end ratio is needed for top speed reading.

[jveik]

yeah one of my buddies told me the way it's set up now will likely only get up to 140 or 150 before it redlines, though i seriously doubt even that 383 can get through that kind of wind resistance... plus i'd probly puss out at 120 lol, or whenever the speedometer needle breaks off on the peg as it tries to pass 0mph on the speedo lmao!!!!

[534BC]

Well, you are trying to push a "billboard" down the road, lol. There is a huge difference in power requirement between 120 and 140 and another huge one for 150. Either way 120 + is very respectable and fast on that truck.

Aside from the gearing issue (which is easy to check or fix) The 450 hp (if it happens to happen right at top-speed) will push a 4000 truck to 120+ in my experience.

Lots of fun, and crazy too.