Posted by Phil on April 02, 03 at 07:15:35:
Last week Spiderman was asking for somebody to talk him into putting headers on his 454, here's my numbers.
My truck is a '93, 454, 4x4, 4.11s, weighed 6,700 lb. that morning with my son and me in it, and 3/4 tank of gas (no tool box!). First runs were with 245-75 tires, air temp 60*. Timed with a G-Tech, the best three of six runs averaged 18.9 seconds @74.6 mph. (Yawn....)
I upgraded the tires to 265-75, and found no measurable difference in performance with the G-Tech. My speedometer was more accurate, though, according to a gps I'm now reading about 1 mph low at 65 (it had been a couple high at that speed).
I got the Edelbrock headers, got them ceramic-coated, and a Flowmaster 70-series muffler. Otherwise stock exhaust system. I also bumped the timing up to 8* btdc (which if I remember right is 4* more than stock).
Couple months later, ran it against the G-Tech again. 6,750 lbs this time (kid eats like a HORSE), 50*, best three runs averaged 17.5 seconds at 81.1 mph. (!) Back in the 60's I would have sold my soul and one of my favorite glands for a 1.4-second, 6.5-mph improvement in the quarter!
The truck is more fun to drive, seat-o-pants really can tell the difference everywhere in the rpm range. Mileage is up about 1 or 1.5 (depending on how much I'm enjoying that extra eagerness). Still running Chevron 87 octane with no complaint, but haven't towed yet (I may fill up with premium for summer trips with the boat on, cheap insurance). The sound is very nice, noise is really mellow, there's virtually no difference from before cruising with the windows closed and Sweetie talking. Just about have to be going up the ramp in an underground parking garage with the windows open to have it be really loud.
I LIKE it!