Originally Posted by Truckshop

in case you are interested. with a 6 inch piece of flat iron you can make the stock truck engine cover fit.

Originally Posted by budhayes3

I know that guys have gotten by with the stock truck intake to about 5800-6k, but that was mostly 5.3's, and at least one 5.7 that I'm aware of. Not sure if their heads flow as well as yours though, but I'm sure that there are more agressive cams in the batch that I'm thinking of.

Originally Posted by hirdlej

You can have joe blow with a stock LQ4, TR224 cam and long tubes, a cold air intake and a tune with NOTHING ELSE DONE but with all other variables the same, he's going to make more power than us and here's why. (remember this is pure theory) When the intake valve opens immediatly after the exhaust stroke, and the piston is traveling downward, on a standard port the air doesn't "slip in" or "slide in" with as much acceleration with all the casting material left as it would if it's ported. The intake port charge is actually kind of stagnant momentarily before it's drawn into the cylinder thus moving less CFM and not potentially "robbing" or taking air from otherwise available intake runners (in the plenum area). With ported heads, and ones that flow exceptionally well, the demand for CFM increases so dramatically that all the cylinders are actually working AGAINST eachother in the higher RPM range and they're fighting over who gets more air. This causes almost a "static" or "cluttered" effect of the intake port pulses. FI guys never see problems like this as they force the air in to make it do what they want it to do. Remember, this is just theory but I think this is what you and I are looking at. I think with better intake manifolds we can attain our 400RWHP level along with even more torque if we plan this right. I don't know though if this can be done with a TBSS intake as after the 90mm opening it bottles down to a 78mm restriction, then opens up again. I don't know if this is gm engineering trying to create a venturi effect for more torque in a heavy truck of if this is an oversight.

Originally Posted by Wilde Racing

throttle body spacer