Originally Posted by matt406
im building a 406 sbc with 1997 vortec heads 092 casting they have been ported and polished on a bench flow they have 202 160 valves screw in studes guide plates 64 cc combustion chambers. it will have 9.8.1 compression, edelbrock rpm air gap intake 600 cfm edelbrock performer carb accel builit distributer hedman headers flowmaster exhaust. i have heard of a similair setup but with stock vortec heads produced 425hp 525 ft lb of torque is this possible or more hp and torque withe this setup
any ideas would help thank you.
As said, the cam specs are needed to make any guess as to power output. But the Chevy 400 will make good power given a good combination of parts; 425 HP is easily attainable. 525 ft/lbs torque can be done as well. Take a look at the the graph under Test 1 (Vortec Heads)
in the article High Performance Chevy Small Block Engine - Engine Masters Magazine
A larger carb like the 3010 Holley 750 vacuum secondary would be a better choice for a performance build of a 400 SBC used on the street. And I personally prefer the RPM intake w/o the air gap if the vehicle will be driven on the street. Doubly so if it will be driven in cold weather.
Tuning the advance curve is very
important. Most distributors need help w/this.
FM mufflers have been shown to be more about sound than performance. You should look into this, check them against other performance mufflers like the Dynomax.
BTW, the L31 5.7L Vortec casting numbers are 12559062