Quote:

If your going to use the 3100 behive springs you have to use the 3100 behive retainers NOT the 2.2 2.5 retainers. You use the 2.2 2.5 retainers with the mopar performance springs, both the mopar springs and 2.2 retainers are a lot more than the 3100 stuff.

The mopar stuff can handle a bigger cam but under .500 lift and modest RPM I have had good luck with the 3100 stuff.



yup, except instead of the MP springs, use the hughes #1110 springs. they're the same price as napa's price on the GM springs, but yeild and extra ~ .040" lift clearance. once I priced it out both ways, I thought the hughes springs were a better value.

for a cam, on my mag headed 318, I had bullet regrind using their HR259/316 lobe for both intake and exhaust, ground on my cam's factory LSA (112). it's a torquey SOB, and pulls hard up to 5500 RPM. idles very clean, near stock, but makes a lot more power. works out to .506" lift, and I have plenty of valve guide clearance. I'm using junkyard 2.2L retainers (got 'em for $10) and the hughes springs and the stock magnum keepers. if you run headers, and especiually if you do a little port cleanup on the heads, they flow good enough on the exhaust that you don't really need a split duration cam. one thing with mine, it is from my '86 short block, so it is an LA roller cam core. I dealt with Tim at bullet. talking with him, it sounds like the LA cores might have a deeper hardened layer, which will allow bigger lobes. beings mine was from a 5th ave (carb motor) it also had the long snout for a mechanical fuel pump.

when looking at cam specs, IMHO, I'd look more at .2" duration numbers than .050 duration numbers. that'll tell you the cam's power potential. for example, my cam's specs are [Email]259@.006"[/Email] lift, [Email]208@.050[/Email], and [Email]127@.200".[/Email] for comparison, a comp XE262 is [Email]262@.006"[/Email], [Email]218@.050[/Email] (10 degrees bigger) and [Email]130@.2"[/Email] (only 3 degrees bigger). this 318 with the roller cam and mag heads feels about as strong as my old 360 with the XE262 with the same induction and exhaust. except it idles much better and gets on average 2-3mpg better fuel economy

I'm very happy with my bullet regrind. another option would be hughes, their HER1828 is the largest they sell as a regrind, and I think is bigger than bullet will regrind on a magnum core. if you want a little more upper RPM power from a bullet grind, I'd see if they could fit the HR266/325 or HR270/330 lobe on there. both will require the hughes springs, the GM ones won't have enough lift capacity (only about .490" max lift from my measurements on my heads)

Last edited by patrick; 01/27/10 09:19 AM.
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