I have a couple in use. First one in my 72 Demon is a 13to1 CR 418/360. 4.03 x 4.100. Bottom end has 2600 passes on it and pistons have never been removed from block since new. Just broke a valve a month back on a friday night. Stayed up late and put a different set of heads on and raced it on saturday night and sunday, same weekend. Won a race with it on sunday. Production heads, 1973 587 "smog" castings, 73 block with no fill, Flat tappet cam, racer brown STX-22. Car weighs 3050#. Been 9.68 at 136mph--1/4 mile and 6.09 at 111 1/8th mile-- 1.26 60ft. I put 30 more passes on it this weekend at Memphis Int. raceway and made it to a final in S/P, 9 rounds. Still went 6.28 at 107.6 after 2600 passes,with lesser ported heads.

Other one is 4.25 x 4.07. 442 c.i. Same 587 production "smog" heads. STX-21 Racer brown flat tappet cam. 11.5to1 CR. 11.20s at 118mph 1/4 mile and 7.20s at 97mph 1/8th mile--1.52 60ft. In a 4200# 79 Chrysler "300". Has 3" exh all the way to the rear bumper with 4 mufflers. Runs on 80% 93 octane mixed with 20% 110 race gas. Made the 1100 mile dragweek trip a couple years ago with no issues.

Both engines have produced best E.T.s with 28* fixed timing. The 79 "300" got around 14mpg on highway during dragweek, when I bought this car in 1987 it only got 12/13 mpg on a vacation to colorado, still 100% stock. Engine in "300" is shifted at 6400rpm. Engine in Demon shifted at 7000 after the first couple months, first couple months I shifted it at 7800rpm. Actually was a couple hundredths quicker at 7800 but I figured longevity was worth more than a couple hundredths. Getting close to $100,000 in winnings with engine in the Demon, $12000 was from wheelie contests. Youtube--dodge demon wheelie 2.


Actually have a third one that is 4.04 x 4.00. Same 587 smog heads. ST-21 Racer brown flat tappet. 93 octane pump gas. 4300# 1990 Ram D150 short bed. 2 3" muffs an X pipe and one stock appearing tailpipe. Muff without tailpipe had an electric cut out at exit. with cut-out shut, the X-pipe worked like a y-pipe and made a single exhaust. Went 12.20s single and 11.80s dual exh until the 727 grenaded and killed the truck and broke 5 bones in my foot. I still have engine but truck is gone. Waiting for the magnum 318 to blow up so I can turn my replacement 92 D150 into a hotrod. Will probably run forever. OK then, when the AC quits blowing cold, maybe then I will put the 410 in, of course with a billet high gear drum in the 727.

Last edited by qwkmopardan; 11/14/17 06:36 AM.