Project Need More POWA

[bilfman]

Well I guess thats why auto companies have R&D and engineers.

So the ongoing love affair of truck and wrench continues. I initially had a TH400/NP203 with 4.56 gears. So when I rebuilt the diffies I went with 3.73's and lockers. Worked well.

Then by chance I found the Holy Grail combo of a 1991 4L80E/NP205, I figure that has to be installed. Build thread here http://67-72chevytrucks.com/vboard/s...d.php?t=537481

Problem was I was then a little lacking in power when pulling my beast of a boat in 4th. 1850rpm at 60. Since the diffies were brand new I didn't want to go through re gearing again. It was also quite close enough that I thought a little more hp would fix er up good.

So I decided some upgraded 781 heads. Port matched and some porting with larger exhaust valves, monster torque grind cam and some roller rockers would put the beast where I want to be.

Feels good now, just waiting for the snow to melt to try the boat behind it now.

First pic is the more restrictive peanut heads, second is the 781's, good comparison shot.