Black6SpdTA

What exactly needs to be done? Other than new springs and stuff, what would the machine shop have to do and how much would it run?

blackztpi

you're going to hafta have the spring seats machined to hold the hotcam compatable springs. (springs for high lift) this shouldn't be much at all. I'm really not sure what all they machine to to make the springs fit perfect, but most of your cost will be from them disassembling your old springsand remounting... stuff like that. while u have the heads there, it might not be a bad idea to have a good 3 angle valve job done or some porting. this will help out the hotcam in achieving all it can for the 350 l98. a good 3 angle valve job is worth a good 15 hp by itself on stock heads. u will also get more power from the cam as well by doing either of these. milling the heads can be tricky on l98 heads because with .525 lift on the valves, a smaller chamber would bring those valves much closer to the piston, however u can probably get away with an .010" mill on stock style pistons. u might want to research that though. well, from what i know personaly, this is all that needs to be done. if there is anytghing else, i'm sure the machine shop will notice and do it for you. good luck to ya

AutoRoc

What springs will you run? Will they fit in the stock spring pockets on the heads? You'll need retainers for them also. And Locks. Do the heads need new valve seals? I'd replace them anyways. Will the stock rocker arms fit the new springs/retainers? It's cool to check piston to valve clearance. Cam Bearings? Goodluck! It's a damn good step up from a stock cam.

Like he said above. Spending money on a GOOD 3 or more angle valve job is well worth it along with pocket porting at the very least. If you look in the area behind the valve(the pocket), it's pretty terrible looking in stock form.

Black6SpdTA

I was going to buy the LT4 Hotcam kit which comes with springs/1.6RR.

insomniac 92z28

The heads really won't have to come off if you stay with the 1.5 (stock) rockers. You can put some comp 981 springs ($60) on it and use your stock retainers. This will save you a lot of expense, but will not make as much power as having the good valve job and pocket porting done, but should still give you a noticeable gain in power.

S. Holley

If your running the l98 heads.... dropped them and get the fastburn/vortec heads...make sure to buy the proper manifold base and you will make 40 more HP than the L98 another 10 with easy with the fastburn version.....

Those number are based off of stock l98 350 cars... with a hot cam and a little compression you will have a fuel injected version of the GM Fast burn motor which is rated 385!

Also they just came out with a 383 version of the Fast Burn.... full warranty and all put out think 460-470 HP

Black6SpdTA

S. Holley please answer the question at hand. I didn't ask what heads I should get.

I won't ever get the vortecs/SDPC base because you have 500 in the heads and 400 in the intake...that's only 300 away from a set of AFR's...but that's an entirely different thread.

Back to the topic- Would I really be better off just getting the cam itself, and then different springs/retainers/locks/etc? Obviously it would be cheaper, any ideas of how much less power I'd make? I won't mind taking the heads off...the engine will be sitting on a stand for a while while I get all the rest of the swap parts together. Thanks for the replies so far!

-Rippin

Black6SpdTA

Hotcam: $175
Comp 981 Springs: $60
Harland Sharp Rockers: $180
Misc. Stuff: $50

That all adds up to 465 if I did my math right...mine as well get the kit.

NOTE: What size are L98 heads--> 3/8" or 7/16"

'92 RS Hybrid-Z28

The springs that come with the HOT cam kit are just barely adequete for 1.6 rockers. I went with Manley 1.25" springs good for .530" lift and 1.5 rockers.

You are talking about the aluminum L98 heads, right? They're 3/8".

Black6SpdTA

Just stock F-Body L98 heads, so aluminum I geuss yeah. Cool thanks.

-Rippin

Kevin91Z

No, f-body heads are iron, the corvette heads are aluminum. Which do you have? I have the corvette aluminum ones. I'm not that familiar with what you can do with the iron heads.

Z28SORR

I used this kit on my 87 Corvette, L98. The only thing you have to do is have the springs installed (valve seats cut and hight adjusted). Shouldn't be more than a few hundered dollars. The 1.6 rockers are self aligning, so you don't need guide plates. In stock configuration piston to valve clearence is not a problem.
Things you can do.... well, all the usual head work. These heads will except over size valves. Can run upwards of a thousand dollars.

Good Luck

insomniac 92z28

Hey,
The F-body heads are cast iron. What I am saying is that the springs in the kit won't work without machining your heads. If you get the comp 981s you can use your retainers and stay with the 1.5 stock rockers, which will clear the head (1.6s won't) and just live with a little less lift. The stock heads won't benifit from the additional lift much anyway so it won't hurt performance much, if any. Just by the cam and the $60 springs and you saved a bunch of cash.

Later,
Charlie

90rocz

One thing not to forget is the "Retainer-to-valveseal" clearance, you should leave a safety margin of .050" even if the springs won't bind. If your retainer hits you seal your gonna bend a pushrod...
While you can buy a "fly-cutter" and machine them on the block, I wouldn't recommend it, you'lll get your motor full of metal shavings and wipe some bearings.
Stock TPI heads will safely only support aprox .480" lift, you could push it to .500", but I wouldn't try .525" of the Hot Cam...

insomniac 92z28

Good point. The hotcam will only have .492 lift with the 1.5 rockers.