Thanks Cab.
Combo 69 Dodge Charger 38-3900lbs
478 Hemi 4.28 bore
4.15 stroke
G101A 4 speed
Advanced clutches twin 8 inch
4.88 gears
10.74@128 @ 3850DA
827hp. Hope the confusion is cleared up.
There should be more in it is all I’m saying. I had the heads off a couple years ago to get them CNC but never looked to see if there’s a part number on the dome. I was told they were 12.5:1 but they don’t look that much different then the 9.5:1 mopar ones that came out of it. It started life as a mopar crate 426.
The first outing this year the car went 11.37@123 with exhaust. When I went again a couple weeks later I took the exhaust off and did a couple jet changes. That’s where the 10.74@128 came from. Then the yoke split in half. If I could post the pictures of my 9.5:1 pistons and the ones in it now you’d see the difference and if I could post my buddy’s piston which is 13.5:1 you’d really see the difference. His is the exact same combo just the pistons are different.
A bit clearer now- the car doesn’t perform to your satisfaction, and the 827 hp came from a dyno test?
There could be a million things wrong here - but if it dynoed at 827 I doubt the pistons are your issue.
According to the calculators you are off around 5 tenths using that altitude. Going from 11 to 1 to 13 to 1 back in the day was worth about 2 mph and a tenth and a half. May be with climate change it’s more now.
