The 78/79 W72 400 is very similar to your 71 400 with 96 heads. This is a 78 400 (with the good 481988 block) that is 0.040 over with forged pistons & rods. The stock 6X-4 heads were resurfaced minimally to be trued and measured 92.5 ccs in the chambers. With .040 quench, it calculated out to be 8.75 to 1 static compression ratio. We used a Summit 2800 cam (204/214/112 @ .422/.444 lift which is very close to the factory original 067 cam specs ) that we had sitting on the shelf with new stock style valve springs. It made 360.3 hp @ 5000 rpm (still climbing) and 456.1 lb-ft torque @ 3600 rpm on the dyno. With a little fine tuning (jetting and timing) it maxed out at 371.4 hp @ 5000 rpm and 460.3 lb-ft torque at 3600 rpm. It had D-port RA exhaust manifolds with 2.5 mandrel bent head-pipes for all pulls.
You dont need to over-cam these engines to make good power.
Dennis
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