which cam should i use???

[chevytech1]

I have a 5.7 out of 1998 tahoe .does anyone know what the lift is on the stock cam and which would be a good upgrade?

[adh383]

Are you gonna do anymore upgrades ? just guessing----- lift is probably around the LOW 400\'s.

[ChevyKiD_69]

i ws going to say the same thing because my engine biulder has checked the lift on a newer cam and it was about 400 lift. nick

[chevytech1]

someone told me the cam specs from all data said the stock cam was I.283 E .291. I am keeping it fuel injected and have bought some high flow injectors. I found a cam at gm performance with a lift I .431 E .451 do you think thats to much for my tbi ?

[adh383]

You can try that cam- its really designed for a bigger cubic inch motor that has a more breathable set of heads. I think you will be dissappointed but, ya never know.

[chevytech1]

even with vortec heads and the upgraded injectors and headers??

[Scotty_S-15]

Might I ask why everyone is concerned about the lift? Sure, higher lift cams normally have longer durations, and vs. versa. But the lift isn\'t the usual critera for choosing a cam.

......... and BTW, the .283/.291 lift that was mentioned was obviously cam lift, not valve lift. After your 1.5 rocker is factored in, that\'d be .425 & .437 which sounds like a normal, stock or mild cam.

[adh383]

Go ahead and try it . I would buy an aftermarket cam with similar specs if you are gonna do it. I saved a good bit of money when i bought a CRANE that had the same numbers that the gm cam had- it worked as well as the gm cam-- it was the 3863151 gm cam which is a flat tappet cam- do some pricing and number comparisions before u buy. Most people judge performance by what you feel in the seat of your pants when you hit the throttle---- thats why i said you may be dissappointed- on the clock you MAY see A MINIMAL improvement--- not trying to discourage you--- just speaking from experience

[Scotty_S-15]

On 2006-06-05 20:25, adh383 wrote:

Go ahead and try it . I would buy an aftermarket cam with similar specs if you are gonna do it. I saved a good bit of money when i bought a CRANE that had the same numbers that the gm cam had- it worked as well as the gm cam-- it was the 3863151 gm cam .................................

Yeah, I think the \"151\" cam is a great cam for a near-stock engine. Lots of guys here however, seems to think that the \"old\" technology of that cam is a bad idea. For certain applications, I think it\'s a great cam. Particularly if you expect an engine with this cam to pile up 100K+ miles with no problems, and to rev to 6K after 100K with the original valve springs. http://www.s10v8.com/images/smilies/icon_wink.gif

.............. I think Crane & GM are joined at the hip, hence them making that cam, and others which are out of production at GM. And, making some newer off road cams for/with GM, including at least one hydraulic roller.

[adh383]

Hey Chevy----- you got a roller right? don\'t get side tracked on a flat tappet. Do the homework.

[chevytech1]

thanks for the info . I do have a roller cam. I think I\'ll try the .431 .451 and see how it works . I drove it for a month with the stock cam so i \'ll let ya\'ll know if there was an inprovement or not. hell its only money!! http://www.s10v8.com/images/smilies/icon_smile.gif

[adh383]

Test and tune-- go for it--- good luck

[QuickV8s10]

We always put LT1 cams in the Vortec motor and they run very well and its cheap... You can find a stock LT1 cam for nothing if you look around and send it to COMP CAMS and let them do a regrind.... The regrind will cost you about $100 and you dont have to change your springs....

[phil33875]

call comp cams, wont take you but a couple of minutes. they can give a real good idea of what you will need. you need to know truck weight, gear, etc.

[coppergmc]

I saw competition products selling stock 5.7 vortec cams a few years ago. Seems like the duration at .050 was 202/206. I would probably stick with the stock cam. I think it is a little bigger than what you are thinking. With no other engine mods, that cam should work fine. If you mess around and get too far out of wack the computer won\'t respond well. If I was going to change anything it might be the rockers. You can get 1.6 roller tip rockers from enginekits.com for 79.95. They actually look like comps and are much tougher than proform\'s junk.

[chevytech1]

I just got the engine in yesterday. No problems so far.Computer is working well . pretty good idle quality.It\'s pretty quick for a stock engine (except the cam) and 4x4.I can tell though I will want more speed and power in the future!! thx for the info..I\'ll try to post some pics.