I am installing a Vortec 350 from a 99 Chevy 3500 van. (The casting on the heads is 10239906, the casting on the block is 880.) Into my Camaro. (Original 305 TPI) The engine came with Vortec heads already done, new stock springs and valve seals.
Please dont tell me to put high lift springs on my heads.
Please dont tell me to get them machined down.
They came from a machine shop and theyre not going back.

I know I am limited to a .480 lift, I am ok with that. As far as the other cam specs go can someone tell me specs to a decent hydraulic roller cam that would fit the stock Vortec heads. They dont have to be crazy and I was considering a stock LT1 cam but ive been told i could do a little better than that. So a decent one please.

Also, a torque converter from an S10. What year S10 V6?

Id love some help thanks guys

The LT1 cam specs come up :201/208 .447"/.459" 10.4:1 112. Thats perfect I want no bigger so why not go with the LT1? Can anyone find me specs for the 99 Chevy 3500 van cam

 

Also Id love to find a the stock specs of the 99 Chevy GMC 3500 van cam. If i went with some 1.6 rockers It might help me more.

 

The Vortec 350's/305's all use the same cam grind. 191º/196º 0.414"/.428" lift on a 111º LSA. there is the HT383/Ramjet350/marine roller cam(p/n 14097395) that has specs of 196º/206º 0.431"/0.451" on a 109º LSA. The LT4 cam from a production 1996 LT4 Corvette(p/n 12551142) has specs of 203º/210º duration at 0.050" and lift of .446"/.450" with 1.5:1 rockers(.476"/.480" with 1.6:1 rockers that the LT4 engine uses) on a 115ºLSA. http://www.fullsizechevy.com/forum/a.../t-436740.html

 

So by going with the .447"/.459" from an Lt1 i can get a little more from it

 

You better check the clearance with as little as .450" on a stock vortec head, .460" is really pushing your luck on a stock head. .480" is a pipe dream on a stock vortec head without having retainer/valve stem clearance issues.

That being said a LT4 cam with 1.5:1 rockers usually just slips in under the limit as it has less lift than the LT1 cam since it came with 1.6:1 rockers stock.

This is what a LT4 cammed L31 dyno looks like, even with the crappy stock CPI truck injection, stock exhaust manifolds, cats, single exhaust, etc.



For a 6,000# brick with only 3.42s in the back it moves out pretty good.


It also has a pretty nice tone to it.

 

If i have no luck finding a cam, Im going to use 1.6 rocker arms. Would i be better using the 1.6s with the 305TPI cam or the 350 Vortec Cam and where will my lift be with the stock heads

 

and what size studs are the ones on the vortec heads

 

I did the math 1.5 to 1.6 conversion and the .414/.428 turns into .442/.457 which is ok by me. All I have to know is will these rocker arms in the link above work on the my vortec heads. If so I am going to order these. It says they arent self aligning does that mean I have to align them and how so? If these will work out ill order them up. Let me know if these work the link is below this.

http://www.summitracing.com/parts/su...make/chevrolet

 

You need roller rockers that are narrow body self aligning. Self aligning is a must unless you plan to upgrade to screw in studs, guide plates, and hardened pushrods. They need to be narrow body to clear the stock center bolt valve covers internal bracing.

You would be lucky to get much over 320-330 HP at the flywheel from the stock L31 cam even with 1.6:1 rockers. Its just tiny and moves no air and the valve timing is meant to make as much low-end torque as possible. The Ramjet cam is noticeably hotter and with 1.6:1 rockers it only makes 350 HP on the Ramjet crate engine.

 

Why do they have to be roller rockers? I believe you I just wanted to know.

 

Just want to subscribe to this thread because I'm working on something similar

 

I understand why they need to be self aligning amd narrow but why do they have to be roller tip. Just wo dering and im very happy with the 320-330 horse

 

http://m.summitracing.com/parts/pro-66927c
Im about to buy these. Just waiting on you guys to make sure these will work. 3/8 stud, same design as the stock rockers, roller tip, 1.6 ratio. Ready to order.