I've got a question for you more experienced folks that stems from my 60-ft time post: Where is my MPH?

My first run with the car netted me a 13.3 at 106MPH and a 2.3X 60'. I took the car out again and ran a 12.84 @ 107MPH and a 2.08 60'. 1/8 mile MPH were 85 and 86MPH respectively. I would think this should be running over 110MPH.

Here's the car's combo:
412ci small block
Heavily reworked camel-humps
12.5:1 compression, 240-250PSI cylinder pressure
Comp Cams 292 Magnum
Weiand Team G
825CFM Mighty Demon
Stock HEI
1-5/8" Headers w/ cutouts
TH400 w/ 3800RPM stall
3.73:1 Gears with 28" drag radials
Estimated 3500lbs (?)

So there you have it. 68RS406 asked me if it "lays down" at the top end, and while I don't think it does, I've never experienced that before to know what that is like. I'm guessing it's one of these key areas:

Bone-stock HEI
3/8" fuel line up to Carter 172GPH pump, -8 thereafter

While I have a hard time imagining a stock HEI sparking 240PSI at 6000RPM, I also can't imagine installing a new system picking me up 5MPH. Same goes with the fuel system. 3/8" should be enough, but I don't know for sure.

What do you guys think? Any ideas?

there was a discussion a while back about how much mph you pick up from from 1/8 mile to 1/4 and it seemed the majority averaged about 21-24mph. So your well within that range. I run 88 1/8 and 110 1/4.

http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/4/19463.html?

Your MPH doesn't appear to be off any. It's really more of an indication of horse power than anything else.
My 70 Chevelle started out running around 13.30s at 105 MPH. With a torque converter change, rear gear change, slicks and open headers, I got it down to 12.00 to12.20s but MPH only went up to 108-110. (this with a 450 HP 454) I then installed a 450 HP 502, and continued to run 108 MPH trap times.
You should be able to get some very low 12s out of it from the power your making.

What Is your total timing?

ANd what jetting and powervalve(s) are in the Carb?

stock hei and 3/8 fuel line you might think is enough.......but thats two things you really can not have enough of as far as im concerned.......even tho you are within the mph pick up range i would have to say there is more there. you should see a gain from a better ignition system....with that kinda cranking compression those cylinders are surely trying to snuff out the spark......and backing that hei with more would sure make it easier for your ignition system to do its job.....and i would bet with an upgrade you would get more of that fuel and air mixture burned to increase your hp in turn would allow for your mph to pick up on the other end and thru out.....as far as the fuel system goes thats an area as well bigger can be better.......increasing to 1/2" fuel line from tank to pump sure helps out its not all about pressure its about volume as well.......i think personaly you would get more of an increase in the ignition system at the moment then the fuel system......

i think with some up grades in these two areas you should find more mph........do you have the carb and timming dialed in for best mph....