1970 C10 (Suspension/traction questions)

[rjcamel2355]

Hey Folks, been digging through this forum/thread and gathering knowledge for awhile now. I've been through the Suspension 101 thread, and picked up some really good information. Hoping some folks chime in and give me some more tips/ideas below is what I'm working with:

1970 C10 Long Bed
408CI LS engine
E85 (Fuel cell located in toolbox in the bed, -12AN feed line, 10AN return line using a magnafuel 750 fuel pump)
Holley Terminator ECU
6766 billet wheel turbos (.81 AR, going to change the housings to a .96 AR)
TH400 with a billet 1/2 brake, RMVB
Front and rear roll pans, drum brakes in the rear, front disc conversion
325/50/15 MT Drag Radial on a 10" rim
12 bolt with 4.11s and an eaton posi
adjustable panhard bar
Truck has been lowered roughly 5" rear, 3" front
Viking rear coilovers with 350LB springs
90/10 Competition engineer front shocks (with 3" front lowering spring) Shocks have been relocated at the tops.
Trailing arm mounting bracket has been flipped
Engine is set back as far as possible, and as high up as possible without altering the firewall

Attempting to leave on 5PSi, making a total of 18PSI. I have not taken this truck to a drag strip yet, been using a local ghost road, but it is very traction limited even using 2nd gear leave it's spinning for the first 35-40 feet. Over 10mph rolling the truck feels great, seems to bite good and pulls very well. It simply refuses to hook from a dig, from videos it seems the front suspension beings to rise, hits its limit, unloads the rear and goes straight to spin city.

I believe my biggest problem is the lack of front suspension travel, which I plan to address in the next week by putting the truck on some scales and getting some weights. I've also picked up an adjustable trailing arm bracket, currently the factory mounts are flipped.