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OK...I am losing sleep at night, and this is part of the reason. I have a 64 Valiant Signet. I am debating a mimic of sorts on Dave's idea here. I have 2 318's to choose from...one Mag and one 302 headed roller from the late 80's. Dave utilised the 273 solid cam. Will it hurt this project to run a roller? And if not, what kind of specs (duration, LSA, lift) should I be looking for? Target CR with quench? Will the benefit of a few less pounds also help? I can go wherever I want with this in some ways...and am seriously thinking that I will go 4-speed. 833 with 2.7-2.9's, or 833OD with 3.2-3.5's? Or chuck it all and do the same thing with a \6? I keep thinking that the theory of light recip assembly gets blown out the window with the 225, as that crank with it's 4.25" stroke ain't light, and it gets tougher to get a cam with specific specs, and exhaust becomes more costly to make it work efficiently (1 of Dutra's manifolds is the same price as Harold's Spitfires...) as well as carb/induction limitations. Just thinking out loud and looking for a bit of feedback before I start into it...

Thanks.



I'd shoot for as much static CR as tolerable (depending on fuel grade) while shooting for a tight quench. I'd use the mag 318, personally. KB167's for pistons, stock rods. the 167's spec out at a 9.588" deck height, I think I'd square deck the block to 0 deck or maybe to ~.008 under, (if I kept them below, I'd use the MP .028" gasket, might net you an extra .1 compression. I'd use the mag heads w/a good valve job, maybe get them milled to clean them up a skoash. I'd play with some of the dynamic compression calculators and shoot for a cam that yields ~8.5-8.8:1 DCR.

cam choice, I'd look for as much lift for as short a duration as possible, probably a wider LSA for less overlap (and it'll help the engine pull higher in the rev range and not poop out at 4000 RPM)...I'd look at something like the hughes HER9204AL or the comp 254HR, & run the GM 3100 springs/retainers.

for tranny/driveline, I'd run an A833OD, 25" or so tall tires and a 2.94 rear.

I'd guess you'd get significantly more power than stock and better economy.

1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)