[BossHogg69]

if the engine shop garaunteed 460-480 at the crank, I'd like to know what heads and cam he's going to switch to gain 100-140 hp! Aluminum heads are fine and good, but there are some 'offshore' brands (Pro Comp comes to mind) that aren't very good - loose valve guides, porous castings, crappy valve springs and what not. Just something to think about before you spend your hard earned cash. Also, I hope you have a really good radiator and fan setup - a true 600 hp is not easy to keep cool. Also, the cam it's gonna take to get 600hp on motor will be pretty rowdy, so make sure you have a contingency plans if your power brakes (if you have them) don't want to work. The cam in my motor is 245* @ .050" and only pulls around 8"-9" of Hg @ a 1100rpm idle. What converter is in that TH400?

As for suspension, I'm running a 468, but with a TREMEC 5 spd and stock trailing arms that have been stitch welded down the seams. I'm using the stock '69 C10 12 bolt housing with a Detroit Truetrac, Moser axles and Moser (Ford 9") housing ends to eliminate the stock C-clips with Richmond 3.73's. I used 1350 u-joints in the driveshaft and converted the trans & pinion yokes to 1350 as well. I also moved my motor back 1.25" in the framerails.

You probably won't be able to hook up even 480 hp (@ crank) on street tires, much less 600. 600 hp is a helluva lot of power, especially in a BB with a bunch of torque. My 468 is in a '69 stepper and i'm running 345mm wide rear tires and they don't stand a chance - I'm talking full on rolling burnouts on the throttle at 50mph slidin' sideways and laughing my a$$ off grabbing gears. Pics are on my profile page if you care to check the truck out.

I believe the Moog 6454 & 6102 springs are the HD/ big block springs to use up front, but you may have to cut a coil off if you're looking to lower the truck a little. The 6454 is a bit taller, but it also has a higher spring rate (1060# vs. 1015#), so depending on the look you're after you might cut more that one coil off to get the look you're after. If you run an iron headed big block, the 6454 might be the better choice. If aluminum heads, maybe the 6102. I'm running 2" drop Hotchkis springs @ 1500#, but they aren't exactly budget friendly. The Moog springs are around $85. Get good shocks and a sway bar too, a big block up front with no sway bar is a hot mess. A junk yard 3/4 ton or 1 ton truck sway bar with new bushings will probably be okay, and much better than none at all. I know from experience. Before I tore my truck apart for this recent build, it had an iron headed 454 with drum brakes and no sway bar up front and was a hand full if you tried to have any fun with it.