kalebm22

iTrader: (2)

my current mods are in the sig. but i was wanting to know what kind of power gains i could see on the stock bottom end by switching to the gm 847 or the xfi 280 from the cc 503
GM847: (234/242 .575/.595 112lsa) w/ 1.6RR's
xfi 280: (230/236 .571/.576 113lsa) w/ 1.6RR's
cc503 : (224/230 .537/.544 112lsa) w/ 1.6RR's

also what do you think my shift points should be with this cam? i was thinking about 6600-6800

gregrob

iTrader: (8)

Xfi 280

bowtienut

iTrader: (1)

From those choieces, I'd pick those XFI 280 lobes, but get them on a 110 LSA and install it at 106 ICL. Probably about 20 hp more than your 503, and at about the same rpm point, which would be great for getting the power to the ground. Much more usable than the power you'd get from the 847 cam.
Just be warned than you'd better have a premium valvetrain to run the XFI lobes. I wouldn't do it for a street motor that is going to see significant mileage. A better choice would be the standard XE lobes, 230/236/110, also installed at 106.

hvyss

I agree with Pat. The XFI lobes are a better choice. I've had the 503 and now have the 847. The 847 is not a real friendly street cam. And good luck finding one. Hard to come by these days.

BOLO

iTrader: (40)

From what I see in your sig, why not just get a matched cam from LE for the LE2 heads you're already running.

86formula

iTrader: (3)

+1 Lloyd knows a thing or two about LT1 cams

slomarao

iTrader: (6)

get a matching cam to go along with your heads. I wouldnt put any of the 3 cams you listed in the motor i am going to build. Its that they are bad grinds, but I think there is alot better stuff out there.

1 Craz28

Niether, you need a Honken Cam! 292 baby!

pillarpod

go custom

kinglt-1

iTrader: (26)

the xe 230 with a decent set of ported stock heads should net 400+ whp and maintain decent power under the curve. If you had a built bottom end then the 847 would work, but it requires to much rpm for any reliability on the stock bottom end. Everybody seems to think a custom grind is the way to go, I agree to some point... Most typical street builds are not going to gain much from going to a custom grind cam. The typical off the shelf grinds will work fine for most, all that custom jibberish is for braggin... Now more radical setups running killer heads, lots of compression, and bigger ci, will definately benifit from a custom grind for sure! I suggest planning out your goals for you car and decide from there.

DroppedM6Z

iTrader: (5)

DITTO

i DID like the pull on my 847 with the LE heads. Just so much better out there now for a few more shiny pennies,

gregrob

iTrader: (8)

Nothing wrong the XFI lobes for street use. Dont let people who have never ran them tell you that. Get a capable dual spring good for .650 lift or so that will give you plenty of headroom and you'll be fine.

I've said it before, the LS guys run waayyy more aggressive lobes than XFI and it doesnt prevent them from putting together some very reliable valve train setups.

97Z28SS

iTrader: (5)

Take this fwiw but I'm building a new 11.8:1 cr all forged, splayed 383 with LE3 heads etc and I have an 847 cam. I asked Lloyd if I should step up to his LE4 cam he told me for a daily driver occasional track car to stick with the 847 cam because it would make just as much power but have better street manners. So that's what I'm doing, by the way my car is an M6.

myltwon

iTrader: (1)

LE cam costs like $300 shipped and an off the shelf costs $260-270 + shipping/tax/etc

no brainer imo, LE ported the heads so he knows what they want

kalebm22

iTrader: (2)

the reason i picked thosse 2 cams is that i know where i can get 2 used ones because i didnt want to spend alot more on this stock bottom end. but after thinking about it i want to have lloyde grind me a cam. i havnt gotten a chance to talk to him yet. but im thinking 234/240 duration. .575 lift 109 lsa
but thats just for starters he can tweek the numbers for best power and sound.

blackz93

iTrader: (2)

Hmmm... mine seems fine. 25,000+ miles on it now with now problems.