Jegs is at it again

[67_C-30]

Originally Posted by 67ChevyRedneck

I wouldn't trust what anyone says. HP ratings are like Penis size... everyone measures it differently.

With HEI and 4 barrel intake/carb anything in the 220-230 range is going to scoot these 3800 lb trucks along just fine, especially with a 3.73 or 4.11 rear. My 290hp 5.3L moves my 5,600 lb 2000 Z71 xcab just fine, and it's 1,800 lbs heavier.

Your 5.3 is rated at 290 net HP, which is close to 370 gross HP. The 260 HP is on the crate engine is the gross rating and the 195 rating is the net rating. The ratings changed from gross to net in 1972. The 350 in 1971 trucks were rated at 255 HP, but the exact same engine was rated 175 HP in 1972. The '71 engine was no stronger than the '72 in the real world.

In other words, if the Goodwrench 350 crate engine could be ordered in a new Chevy truck, it would be rated at 195 HP instead of 260 HP. Every crate engine sold is rated in gross HP because of marketing. A 260 HP engine sounds way better than a 195 HP engine.

This is why LS swaps have gotten so popular. A junkyard 290 HP 5.3 makes more power than ZZ4 crate engine, even though the ZZ4 is rated at 355 HP.