r.barn

you need aftermarket heads and cam, will give you the performance you're looking for.

www.thumperoforangepark.com has a nice "proven 12sec" combo for $900

2 kwik

yes I bet but they don't have suppension mods.....I have done cars that run low 13's with a basicaly stock engine....

FullAuto

With the minor changes you made to your car, a slight change in temperature or humidity could have made them seen nonexistent at the track.

OJMiles

Anybody here running those thumper modified heads? seems like a deal to me....

-- Ojm

FullAuto

I've used them previously. They are a very good product. They have a nice finsh and performed well for what I expected. But bang for the buck, they are not a good buy. I knew that before I ordered them though. I was building a sleeper and didn't mind paying extra to keep it the way I wanted. So keep that in mind before you shell out the cash.

SpooledupRacing

what gears should I run for best street and track use?

Dave

r.barn

3.73's
I actually think the the thumpers are a decent deal, they flow with GT-40X heads and what most people
forget when they look at the $700 cost vs. $1,000 alum. heads is that the Thumpers come with upgraded
springs for that price. You would have to spend another $150-200 on spring set to be fair comparison.
so it shoud be $700 vs. $1,200, and hey $500 will buy you a new intake manifold and cam for what you would
just spend on aluminum heads.

FullAuto

But you are comparing them to a new cylinder head. You can pick up all kinds of used aluminum heads in the $800 range and they will simply slaughter them in terms of flow out of the box and have all kinds of potential for later. And with the cost of shipping a set of stock iron heads to cover the $100 core charge from Thumper, you might as well throw that in to the cost also. With the upgraded valve springs on the Thumpers, you'll either have $800 in them or $700 + shipping on a set of heavy iron heads. So if for a little more you can get a set of Twisted Wedge or Performer heads, that would be the better deal.

SpooledupRacing

373's eh? and if I swapped to those what would that put my at as far as trapping.. 3rd gear or 4th gear? (5 speed manual trans)

also what is stock gearing on these

ZachW04Stang

$700 for heads that flow the same as GT40's stock??? Why not just buy a set of gt40 heads and port them and you'd be even faster.