Big Block in a 4x4

[hllblly1972gmc]

I dont know how much help I can be because I changed a lot on my truck. Its a 1972 GMC 4x4 1/2/ ton short bed. I built all the cross members, sirewall, linkages, etc.... I copied this from another post I replied too, maybe it will help some of you. Or some of you will think Im crazy.

I have a 1972 gmc 1/2 ton 4x4 short bed. Still building, but should be done in the next few years I think. I built a 520 CI BBC. For headers I have the Hookers Super Comp, or Pro Comps cant remember. They fit good so far, but may run into some issues around the transfer case. Also these headers kinda suck because they have thin mounting flanges, I will build new flanges for them where they mount to the heads. I did trim the frame a bit. I am using Merlin heads, so the exhaust ports are a little higher than stock heads, about a 1/4 inch or so. I moved my firewall back 2 1/4 inches. I cut out my firewall and fabbed a new one. The firewall sits about 1/4 inch from the plastic heater box inside the cab. I built a new crossmember, and am using big block mounts. I lifted the body 1 1/2 inches, I cut three inch blocks in half because I didnt want too much lift, already have a six inch suspension lift. As far as the question about the clutch linkage, I ground the old bracket off the frame and moved it so it would match the pivot ball. Then made up new rods for the linkage to adjust for length, also due to the firewall change, my clutch linkage off the pedal is also different, it goes through the floor about two inches further to the driverside. I use tall merlin valve covers and have no clearance issues with the brake booster or heater box, this is a non a/c cab.

I know this reply is long, but theres been a lot of work here.

Im the Be-Cool radiator. My engine is very large displacement, If anyone wants info on it just let me know. Its naturally aspirated, should dyno out at about 620 to 650 horsepower, when I get the truck together I will dyno it at my work, its nice to have a dyno. Also am going to be running a 250 hp nitrous kit, not added into the hp numbers above. Be-Cool makes a radiator for our trucks that will cool up to 900 hp, I think it was about 500 dollars, give or take a little, but not much.








Maybe this will help someone. I am going to alot of work but I want it to be right. If anyone has any questions of anything I did, or maybe something I did wrong

This is the same reply as I did to a few other threads.