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Hey guys, just a quick question: how much horsepower and torque on average can the stock transmission(c6), transfer case(np205), driveshafts, and axles (9inch in back and dana44 in front) hold up to? the truck is a 79 f150 supercab with a "trac lock" rear end and big tires that stick to the road really well. also, how much power will the stock 400 block, crank, and rods take before things start to fall apart?
The driveline is pretty stout, the weaklink is probably the Dana44 as suggested, I think they'll take about 400hp pretty easily since the front has an easier job (usually). I know a guy with a 408w Bronco that broke Dana44 axle in the sand and he's around 450hp. I'm assuming no rock crawling, 150hp is enough to break about anything in the rocks. I'd say 450hp is around the limit with the 400, with the weakest part being the rods. They're not especially weak, it's just that the block and crank are known to be very stout.
I think torque is the limiting factor. You could have 700 HP and little torque. Just think if you stuck a 3408 Cat engine w/ it's 1300 ft/lbs of torque up front. It could have 300 HP and still tie your drive train up in knots.
I don't have a dyno, but my 400 is suposed to put out 580 ft/lbs of torque. I crush the needle bearing in the driveline really easy, and I've yet to hit full throttle locked in 4WD
Thanks for the info guys, that was exactly what i was looking for. to 400HP794x4, what exactly did you do to your 400 to be supposedly putting out 580 lb\ft and around 400 hp? are you using the stock rods? i would guess you have the high compression pistons, a good cam\intake\exhaust, and maybe some head work... anything else? how long ago did you do that work on the engine, and how hard have you been driving it since then, any problems youve come across?
hmmm, you mean a stock rebuild..with those extras you mentioned? i could maybe see it with decent compression, but otherwise, not a chance. 400's are rated at under 200 hp stock, and i know from experience that a basic rebuild, 4 barrel, and port work isnt good for much (i dont have that great of a cam but i wouldnt expect over 150 hp from a cam alone)...390GT-where are you getting your #'s for that? , and 400HP79- what all does your engine have?
400 is under 200 hp factory due to its weak smog cam and something like 300 cfm autolite 2 barrel that motor cant ever breath i believe with a good cam, intake and carb 9:1 pistons you could easily get that much power out of it