...BUT...your 4-speed will easily allow driving with a stock motor, just not much heavy hauling at speed (or drag racing ;))
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I do a lot of heavy hauling. so much that the axle hits the rubber blocks on the frame. always goes 65 mph down the interstate. and that's with the stock 235.
anyway, I might keep the hydros. I'm afraid I'll miss the sewing machine sound though. Rings bearings etc was already planned, just as a head job, did one to the engine that's currently in the truck and that turned out to be some well-spent time. If this head is still straight (whcih I still have to check) the work on the head is super cheap as well, lots of gain for little $$
