I'm pretty set on getting a gm847, but I've been thinking about the 239/245. I know the 847 makes power to 6700, but not quite sure about the other one. Will the other one be that much different than the 847?

Here's what I'm running

355ci
-balanced rotating assembly
-ross forged pistons
-eagle Ibeam rods
-ARP main studs+head bolts
-stock heads port match comp ratio 11to1
-cloyes double roller timing chain
-cc1.6 RR,pushrods,springs,rocker studs
-mezeire HD electric water pump
-hooker LT coated headers
-clevitte H-series bearings

I plan on getting 987 springs for the new cam setup. I don't really give a flip about streetability. I'm only going to drive the car a few miles a year. Which on will be quicker in the 1/4 w/my setup?

 

ttt

 

what lift?
thats almost the same cam alan at FMS designed for my 383 (238/245).
i told him i wanted a big cam for daily driver and still maintain good vacuum for brakes.

if you dont care about streetability, you can go alot bigger than that.

but since your heads are only portmatched, why dont you get a full portjob on them so the cam makes more power.

 

because for now, i just want to make max power with the stock heads. i can't afford a port job.

 

Get the recommended stuff from the cam maker and don't depend on someones advice.

 

You mean custom grind?

 

i think he meant tell a cam designer your situation and let them choose the cam specs and pick out your springs.

 

Exactly......

 

give compcam a call

or competition motorsports

www.cmotorsports.com they helped me choose my turbo cam...

but honestly gm847 with heads and a 355 would be a great combo... you need to tell us the lift as well...

 

If you call Comp make sure you are talking to someone that knows their stuff. A lot of bodies at Comp don't know what they are doing.
A speed shop will sell you what they sell,maybe not what you need.
You need to talk to a cam maker that has a GOOD Tech Dept. There are several, so call around and compare,Reed,Isky,Crower, Cam Motion,
.

 

how do i know the lift?

 

look it up on the Cam makers website. I've read your posts before, i really think you should research this cam decision alittle more than just slapping in a cam and going. The cams you have listed are pretty diff.

 

here is a comparison of a the GM 847, comp 306, and the comp 239/245, lift is with 1.5 rockers...

----- duration ----- lift @.050 ---- LSA
----- int / ex ------ int / ex

239/
245: 239/245 ---- .541/.541 ---- 112
306: 230/244 ---- .510/.540 ---- 112
847: 234/242 ---- .539/.558 ---- 112

hope this gives you some helpfull info...

 

I'm using 1.6 roller rockers. what does that change?

 

ttt