Cntrvrsy

I have an early pre '86 350 block and wanted to know if the step nosed LT4 HOT cam can be used?

chevyboy07 91

the 86 block you have is most probably a "non-roller" block. The LT4 cam is a roller cam. The combo should work fine, but you must use the proper lifters for the cam.
I know for a fact you can run a non roller cam in a 87+ block so long as you also use hyd. lifters as well. The lifters just drop right in.

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Alex A. (aka chevyboy)
1992 Z-28 L98/1LE. Heritage Edition. SLP runners, gutted cats, SLP 3" cat-back & muffler. 3" flo-tech cut-out, SLP TB foil, K&N filter @ TB, 3.23 posi rear.

Guest

Unfortunately, no it cant. The step on the front sticks out past where the earlier cam would, so when you put the timing gear on there it would force the cam too far back into the block.

If you really want to use that block and want a roller, get a 'retrofit' kit from your favorite manufacturer.

Cntrvrsy

Thanks 4 the replies. The block I have is a 4 bolt '70 something from a truck. The step nose part is what I was wondering about. I wondered if I used the late model timing gear set with it will it work out then? I read that the late model roller cam gear set has a recessed area in the cam sprocket where that "step" fits in2.
The particluar cam I was looking at is a GM roller cam (12370847) 234/242 @.050 .539"-.558" w/1.5 rr's 112 LSA. It only comes in the step nose design .

TPI Guy

Yes, the cam will work. If you have looked at Lingenfelter's cams, you will notice that they only offer 1 roller cam grind. They also offer a 420 cube engine, in that engine they put their cam ... so I called them, all you need to do is buy a button, and the timing chain from an 87+ small block.

Chevy High performance also described an alternate process for the retrofit. They claimed that you could simply buy the cam retainer plate, trim off the "ears" buy a button and a roller timing chain ... this was specifically for the HOT cam...

Cntrvrsy

Thanks TPI Guy. I remembered reading somewhere about the swap but I couldn't remember the details about it. I know in 1 of the latest issue of Chevy High, they put an early roller cam in the '87+ block with a button and thrust plate. I just couldn't remember if the opposite was done.

TPI Guy

Let me know if you end up doing this, and how well it works.

88IROCs

You mentioned in your first post that you wanted to use the LT4 "Hot" cam(p/n 24502586 - 218/228° @ 0.050", .525"/.525" w/ 1.6 rr) but in your second post you quote the specs and p/n from a totally different cam(which is GMPP's largest sbc hydraulic-roller, but would be marginal for a street-duty 350).

Which cam are you actually interested in?

btw, LSA and LCA are not interchangeable. In your second post, you quoted the LSA as 112°, this is not correct. The LCA is 112°. It's impossible to calculate the LSA without valve events data, but a cam that large probably has 110° or less LSA.

[This message has been edited by 88IROCs (edited November 07, 2001).]

Cntrvrsy

I was just curious 2 know if the late model "step nose" design roller cam would work out in an early "non-roller" block. I only mentioned the LT4 because that is the most popular of the "step nose" designed cams and every1 here would know what I refering 2.
The 2nd cam I mentioned is the 1 was some what interested in using. In a round about way I was told that is the cam that SDPC used in their 465HP version of GM's ZZ430 crate motor. But more than likely I'll be going with CompCams line of Xtreme Energy HYD roller. Perhaps their 288HR.