So my ported LT1 heads are coming in the mail and I need to decide what to put on them. I'm going to use a GM847 cam, and i would like to use as many GM parts as possible. Any suggestions as to what springs/rockers/lifters/pushrods i should use?

 

Seriously, no one has ever tried to do an all GM valvetrain for the 847 cam?

 

Not really a good idea since you can't get enough spring from GM to do it.

 

The deal with GM valvetrain is that GM doesnt actually manufacture any of it... I believe all the parts youd get from the dealer are manufactured by Crane but of course it will ahve GM or AC stamped on them. Like the RRs for example might be silver in color with a GM part number but they are physically identical to the crane golds.. in fact they are what GM throws in the LT4 hotcam kit.

 

crane golds and gm bowtie roller rockers (what is in the hotcam kit) are not the same. the crane gold are much stronger and hold a higher lift. i think the materials are even different.
for your setup, i'd run GM guideplates, arp rocker arm studs, comp cams pro mag rocker arms 1.5 or 1.6 (whichever u prefer), and a good chromoly pushrod to top it off. i got my guideplates from gm parts direct for like 2 bucks a piece. summitracing and used stuff from the board isn't a bad idea either. i got my promags used and rocker studs. all in great shape and saved a ton of money

 

I read that directly from a Jegs catalog...

 

if i were you, i'd run comp cams beehive springs and run stock lifters. bret bauer instructed this to me...and well he's pretty smart.

 

That may have been what he suggested for your particular application, but my exhaust numbers don't peak till about .600 lift and my intake at .580. Which i believe is fairly close to the 847 with 1.6 rockers. And the reason I'm trying to do all GM stuff is that i can get it fairly cheap if i can just pick out the part numbers. the 366282 dual springs with damper say they are good for a .625 lift, is this false information? And will the aluminum rockers P/N 12361322 with 7/16 studs not be sufficient? Anyone who is sceptical of stock GM stuff just take a look at some of their motors they have made in the past, they've done pushrod engines for a long time now.

 

did you try the GM performance parts website?

P/N 12361329 will get you 16 rockers

 

I have a friend that is selling ARP rocker arm studs.... if interested let me know (via PM please)

 

I would go The 7/16 rockers and studs. Make sure you can set the springs to the proper height as well.

 

the gm bowtie self aligning rockers will not be sufficent, as they are only good to .570 lift. you will want to go with comp cams pro magnums that are NON SELF ALIGNING. pick a ratio as you please. also get pushrod guide plates from gmpartsdirect.com. My cam peaks around .600 also, so you will be fine. if you want to go cheaply, you can always get a set of CM 612 springs which are good to .600 lift. From what i've been reading, beehives are the way to go. you will need 7/16 studs, and 7/16 rockers to fit them. i think gm does make a rocker capable of doing what you want, but pro mags, are more than not, voted the favorites. i got mine for 200 shipped, used on this board. like 3k miles, and they look like they are brand new.

 

Looks like i'll have to go with the Aftermarket rockers.....turns out the only rockers GM makes that can handle a .600 lift are 1.7's for big blocks. Thanks for the advice though. Final setup:

GM 847 cam: 12370847
GM pushrods: 12371041
Roller lifters: 12371042
GM springs: 366282
Comp cam rockers: so close

 

Wait a second.....why do i want non-self aligning rockers? Then i have to buy guideplates for them right?

 

Nevermind, probably because the self aligning only come in 3/8 stud, correct?