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View Full Version : Jay reguarding .904 lifter sbc.


Ed Kurzawa
06-23-2006, 10:11 PM
I have been folling the previous thread on this. My question is I know that the larger lifter helps stabilize the valve train, but what effect does it have on power output? I read an article in a mopar mag. years ago that said mopar flat tappets acted like a solid roller cam if ground properly due to the large footprint the lifter made on the cam. I could be very interested in doing this right now, because my shortblock is not assembled yet. My heads are done.New but older World products 200cc aluminum 202/160 bowls blended all sharp edges smoothed out. The springs are Comp 950-16 installed at 1.900. They told me I could safely go 620 lift with solid flat tappet. I don't want to change anything in the heads as they sit assembled. All the hardware is also Comp. 10 degree locks molly retainers molly spring cups. The cam is also Comp ,solid flat tappet 532IN 555EX 250IN/260EX@.50 282/290 . We are using this for a baseline setup because this is a totally oneoff car. 1941 Chevy home built bracket car.Also motor is 355, 12-0 to 1 zero deck eagl rod,steel crank, Super Victor intake, 750 Holley HP. I can return the cam,to Jegs box never been opened. Forgot, 1.5 Comp ProMagnumn rockers. Have not bought pushrods yet. How much would I benefit if I went to the larger .904 lifter bore and had you grind us a solid flat tappet. I definately don't want to get into a bunch of block mods I can't do at home,other than getting the lifter bores honed by my machinst. This is a stock GM 4bolt block w stock oiling in the block. The car weighs about 32 -3300 max. Turbo 400 w brake, will be a Chance 8in convertor,456 gear, 28 x9 tire, based on the Comp cam. I know I said a mouthful but Iknow you would need the info. to compare to your thoughts. Also ,would this use a Mopar lifter or a custom built lifter,obviously cut to length pushrods, I definately do not wan't to run a roller set up in this motor. I like the thought of a low maint. motor for now. Thanks, Ed SR.

68 nova 10.5
06-24-2006, 12:35 AM
My brother has that same cam in his 73 nova it runs 12.50's @ 3500 lbs its a 331 ,10.5-1with camel humps unported , vic jr 600 dbl pumper hughes 10" 3500 & a 4.10 13/4" headman headers & 3" exaust with 2 chamber flows It sounds radical and pulls hard trough 7000 sounds like your combo should get you well ,well into the elevens just ramblin.......................................

Jay Allen
06-25-2006, 10:53 PM
But using a .904 lifter right now ain't gonna work *IF* you must use what you have.

You'll need PR and you'll change springs. The .904" Mopar lifter with a cam that takes advantage of that lifter will be as aggressive if not MORE aggressive than a SBC .842" lift with MOST solid rollers.

It'll work. But you'll have to change some parts.

Tough decisions.......