im probably gonna buy a new cam on friday when i get my paycheck.

i have a 350HO with vortec heads, and i was thinking of tossing in something a little bigger.

i'm either going to buy a comp cams XE262 or a XE268, the car is a manual so there is no issues with a torque convertor.

im pretty much split between the two.

im pretty sure i could still get through emissions with the XE262 no problem, and i think i might be able to get through with the XE268.

im allowed, 3.00 HC's, 25.00 CO's, and 3.50 NOX's, so my emissions are pretty lenient.

the XE262 would have better street manners(daily driver), but i don't want to buy a cam, put it in, and still be wishing i had went bigger.

i know people reccomend the XE274, but that is too big for me, i still like having kind of decent mileage.

also, considering my motor only has about 2,000 miles on it, should i buy new lifters, or are the stock ones fine because they are so new?

 

You'd be on the hairy edge for lift on unmodified Vortec heads.

You'd be better able to pass sniffer at idle with more LSA.

 

I don't think the XE274 would be too big at all. That cam is very well manored and would probably give you the best gains. If you have the stock vortec valve springs though I'd watch out. Atleast go with the XE268. I'm assuming your car is non-CC carbed though?

You should never re-use hydraulic flat tappet lifters unless you have the surfaces machined flat again. They wear to the specific cam's pattern that they were broke-in with.

 

thats what im thinking. the only thing i was worried about was the 110 LSA

i would go with the XE274, but i think it is a bit too big to pass smog. i heard as a rule of thub to keep it under 220ish degrees intake duration, and the XE274 is 230..

as for the springs, the XE262 has only .469" on the exhaust side, the stock cam has .460" so its too much bigger.

and this is mostly a street motor, so its not like it gets trashed every weekend.

my biggest question is, with the emissions numbers posted in my orignial post, do you all think i could get through smog with a XE268.

110LSA
224/230 duration @0.050
.477/.480" lift

 

Theres no real way to tell other than actually trying to pass it. I'm 95% sure though with proper tuning it'd pass. The lift isn't what you should be worried about with the springs. Those springs are designed for a lazy slow reving truck cam. Throwing in a more up-beat cam with faster ramps may cause them to float or break. At the very least you should buy some 1.25" drop-in replacement springs. There is nothing crappier than dropping a valve and it destroying your entire motor because you didn't replace a not-so-expensive component.

Once again, you'll be alright with the 268 (power, drivability and gas milage wise) Some guys on here are running low 13's with them and vortecs. If you wan't to pass emissions with absolutely no doubts you should select a similar cam with, like, at 112-114LSA. But either way, I *think* you'll be alright with a good tune.

 

thanks, yeah im probably gonna go with the 268. until i either take the heads off to port them, or get new ones(which i don't plan on doing for a few years), im not gonna machine down the vavle guides, so i suppose i could get a set of like K7's or i think scoggin dickey has a set of 1.250 valve springs that are better than stock.