89 irockz

i have a 89 irocz its been converted to a carb motor and it has a edlebrock performer intake a 600 holley a full exhaust and it has stock heads and springs and im wanting a cam that will make it pull way up into the rpm does anyone know what i can get

ASE doc

LOL. You know this thread will probably turn into a forum of differing opinions. My best advice is use Comp Cams cam selection tool. Your combo is about as plain jane and common as they come. The cam selection tool should work well on in. One quick heads up, the major weak link on the TPI motors is the crummy stock heads. Don't expect much out of them without port work. The stock springs are good to about 5,500 before valve float.

oscarfromla

iTrader: (9)

I would try both Comp Cams as ASE doc suggested, and I would try another cam manufacturer to see if the grinds are similar (they won't be the same but they may be close). I knew what I wanted my car to do, but didn't know how to pick a cam so I called Mike Jones of Jones Cams. I told him what I wanted and the combo I had and he gave me his recommendation, which I purchased.

ASE doc

That's a good point. With Comp's cam recommendation software, you're getting a recommendation from computer software. By calling someone like Mike Jones, you get to speak to someone who has extensive experience in matching cams to engines.

From my own engine building experience, I would say that you would be good with about 220 degrees of intake duration @.050, if you leave the heads as they are. If you plan on porting the heads, you can go with 230 degrees @ .050. That's about 270 degrees advertised. Exhaust duration will generally be about 10 degrees higher than intake. The stock heads with a spring change can handle at least .480 lift. With work on the guides, they can handle over .500. Depending on what you plan to do with the heads, choose a gross lift in this range.

Gross lift is based on a particular rocker ratio. Be sure to verify what your actual gross lift will be with whatever rockers you use. Gross lift is simply lobe lift x rocker ratio. I recommend narrow body(Crane Gold Race, Comp Pro Magnum) roller rockers. LSA for your carbed, dual plane application should be about 108-110, 108 will give a more lopey idle and make peak torque at a lower RPM. Since your 87 350 is already hyd roller, I would definitely stay with that. With your heads left stock, using upgraded springs(talk to whomever you buy the cam from for spring recommendations), this combo should be good for about 300hp. With porting and machining of your heads and the larger cam that this will afford you, you will be closer to 350+hp.

Look at Comp Cams and view cam spec sheets to match a cam to these recommendations, if you want to go this way. Or buy the cam wherever you choose. I personally began using a custom cam grinder, Oregon Cams, here in my area because not only can he cut me any cam that I want, but he is less expensive and faster than Comp.