jonathan0292

I am currently installing the GM 847 cam into my car. I have 1.5 rockers and the factory 3/8 studs and I do not know what springs, seats, locks or retainers to use. Also should I get new push rods? Any help would be great. I tried to search the subject but the search would not work for me.

96TurboWS6

I used beehives when I had the 847 and they worked great..and yes get one piece chromeoly pushrods..trickflows are around 90$

GREGG 97Z

Are you reusing the stock stamped rocker arms? That sounds like a bad combo with a cam that size, or any cam upgrade. I would suggest going with some decent roller rockers with that cam. For the springs, Crane makes a good spring kit for stock LT1 heads, pn # 10308-1. It includes dual springs, seats, locks and retainers. I went with this kit for my rebuild, just upgraded the seats in the kit to L98 seats based on many recommendations here.

godspeed1976

I dont know much about that cam, but if your on a budget the LT4 valvetrain is a good way to go. Here is a PN# list of all the items used in a Hotcam Kit minus the 1.6rrs. From what I have learned the 1.5 rockers that come in the LT1 are pretty weak and should be upgraded when you go to a bigger cam. Proform makes a very inexpensive set of 1.6rrs as does Summit. Most ppl will tell you to that Comp and Crane make better ones, and I am sure they do, but we all can't afford them.

GMPP - LT-4 Valvetrain
16 valve springs P/N 12551483
16 valve caps P/N 10212808
16 valve keys P/N 24503856
16 valve spring shims P/N 10212809

As far as pushrods go the stock rods are hardend so they work well. Inspect them when you are doing the install, if you have any questions about them then replace it. If you don't see any problems with them then reuse them. Same goes for your lifters. Just my budget .02

Purplemaroz28

id recomend gettting comp pro magnum roller rockers,comp factory replacement lifters, hardened pushrods, beehive springs, and gm guidplates better safe than soryy.

jonathan0292

no I am not reusing the stock rockers I have a set of crane cams gold roller rockers 1.5 ratio and the total lift on the cam will be .539/.558" with the rockers, and I do not know what springs would be good because I do not want to float the valves at 6000 RPM because I plan to go to 7K, I have had all internals on the engine balanced and a complete rebuild of the engine.

jonathan0292

do any of you know what the max lift is on the Crane Cams kit Part Number: 10308-1 and if it would with the cam and rockers I have? I believe that the max lift would be around .600 and if that is the case than I do not see why it would not work, any input would be great.

DirtyDaveW

To install the 10308-1, you have to remove the stock seats. In doing that, you need to remove the valve stem oil seals (the seals OD is larger than the seats ID). So replace the seals with new ones. As long as you use the 10308-1 kits retainers, the Cranes will clear. But, if you opt for a titanium retainer (for lighter weight) be aware most of them have larger shoulders and can actually contact the underside of the crane RR. This would make the underside of the rocker actually open the valve via the retainer instead of the tip of the rocker pushing down on the valve stem. Ask me how I know (this is the reason I have a new 383 and large unpaid amount on my credit card). Some of the parts sites list separate valve seals for the Intake versus the Exhaust, some list the same part number. I don't know if it's *that* critical. The L98 Seats are a good solid seat. The 10308-1 kits claim that they contain seats but it's actually more like some spring steel shim stock. I tried just those the first time and would occasionally find a shard of the seat on the magnetic drain plug during oil changes. At the proper installed height (1.75" I believe) the springs are good to .600 lift. I ran these springs with my first cam (LT4 HOT) and second cam (CC 224/236) and they worked beautifully. It was when I went to the Cam Motions Hyd Roller and attendant springs that I opted for the Titanium retainers and invited disaster (The constant side loading of the retainer/springs metal fatigued the L98 seats, they snapped apart and the metal got between the cams oil pump drive and the drive gear, shearing off all the teeth of the drive gear).