Will Comp Cams Magnum Rocker Arms 1.52w/ 3/8" stud work with a stock 86 5.0L TPI motor? Wll be upgrading to a better cam too later but thought ill do this first. Also any recomandations on a good streetable cam?

Thanks Alex

 

Don't bother with 1.52, go 1.6 roller tips, benefit from the added lift, especially with the "peanut-cam". Read the thread shown below:

https://www.thirdgen.org/techbb2/sho...hreadid=248402

 

ok i see the good in going w/ 1.6 roller but will can i use self alinging or dont i need it b/c i have 86 iroc and all the self alining say 1987 and later years? Also will i have to do any prom changing or should it run fine w/ stock settings?

 

You will be fine on the PROM. You can get the non-SA. If you want to double check, look at the tip that makes contact with the valve tip. If there is a small recessed portion, that fits nicely on the valve tip, you need SA. If there is no recessed portion, you need non-SA.

 

"oblong-us", I would definately go with 1.6 Comp roller tips. In fact, I soon will do so on my non peanut cammed 85 TPI 305. We recently put a set of these on my buddys 89 L98 Formula, along with a fully ported TPIS "big-mouth" base. This definately made his pull stronger, esp in the 2500-5000 range. His 700R4 has a 'vette servo, and previously he'd get a "chirp" on the 1-2 shift @ WOT. Now, it lights em up on the 1-2 shift @ WOT. In addition , it actually gave the exhaust a more aggressive note, especially at idle. The idle is not lopey, but it "throbs" more than before, sounds great. He is pleased with the result for the effort and cost involved.

To me, on a stock cammed engine, the 1.6 roller tips are a sweet addition, short of a cam. At the very least, the rockers are all a true, accurate ratio, unlike the stock, which are known to vary considerably. And if you were to go to a larger cam later, you could re-use the 1.6 rockers. Just keep the added lift these provide in mind when selecting future cam profile.

 

You can also use the non self-aligning on the L98 Iron heads, too because the pushrod holes in the heads are small, thus aligning the pushrod with the rocker.

 

Well i need Non-SA b/c their is not a divit in the rocker where it meets the spring. But the comp cams 249-1416-16
1.6 Ratio, 3/8'' Stud, 16/pkg, (*) (**) says it "May require machine work to the head. " so will i wont i need to have the heads machined? thanks for all the posts they are really helping me.

Also wuts so funny about my sn 1991 RS 305?

 

The "machine work" they refer to is enlarging the pushrod hole / slot so the pushrod will not rub on the slot due to the rocker ratio changing the angle of pushrod. Again, we did these on my buddys L98. His cam has lots more lift to start with than your "peanut cam" will end up with. He went from .415/.428 to .443/.458 with no slot interference problems. Your peanut cam starts out with something like .350/.385. With 1.6, you'd have .373/.411, still mild, but an improvement. To determine added lift with 1.6 rockers, take the current lift number, divide it by 1.5, then multiply that number by 1.6:

.350 / 1.5 = .233 * 1.6 = .373
.385 / 1.5 = .257 * 1.6 = .411

You should have no clearence issues, I'd still turn it over and observe it to be safe.

 

Perhaps that is the machining they mention, however, i have a feeling that isn't what they are implicating. I am more certain that the machining that they are talking about is the vavle guide bosses. Obviously, because you are increasing the lift, you are increasing the space needed between the valve guide boss and the bottom of the retainer. I have seen it a few times where 1.5 rockers fit and 1.6 were too much and the guide boss needed to get milled down to increase the clearance. It's the #1 issue that needs to be addressed when looking to increase the lift. Factory clearance allows for about .470" or so lift, more or less. Anything more than that and the guide bosses need to be milled down, like i said.