LewisL230

I’m building a 1983 4 door Malibu. Yeah let that soak in. It’s a complete grandma car. Im wanting to build it street strip, but more toward the strip. I really want to race it but still be able to cruise with the family in it. I’m swapping in an LC9 5.3. It will have a dual plane intake and 750 Holley on it. Converter, I’m not sure of, will be dictated by the cam choice. This is a budget build so the Summit cams have stuck out to me. I’ve looked at the 8708 and the 8702.

The 8708 is 231/242 .600/.600 113+3 LSA

The 8702 is 236/242 .612/.612 110 LSA

Would either of these be a good fit for my build? And would anybody think I would have any PTV issues with either of these?

Also would beehive springs work with the 8708 or would I need the dual springs as I noticed it’s offered with both. I will not be turning it super hard, maybe 6500 at the most.

I posted this In the carb forum, but it doesn’t seem to get very much traffic anymore, my apologies for the double post.

dreadpirateroberts

iTrader: (1)

https://ls1tech.com/forums/generatio...ce-advice.html

LewisL230

Yeah that was actually my post, I wasn’t building that truck for the street. Before I ever got started on it, a friend offered me money I couldn’t turn down so I sold it. This car I would like to be a little more street friendly.

68Formula

Both those cams are too big for a 5.3L if you're only planning on turning to 6500rpm. Your engine won't even reach peak power by then. Go with the SUM-8720. You'll want at least 3000rpm stall and some 3.73+ gears.

99 Black Bird T/A

iTrader: (4)

Family cruise car, want to race, LS powered - could a 08 V8 Grand Prix for around 5 to 7k might be worth a look?

Otherwise +1 on what 68Formula said.

camarozz383

iTrader: (3)

I have a 54-600-11 comp cam in mine, great cam imo

Darth_V8r

iTrader: (4)

Please, oh please, tell me it's the wagon!!! That would be the coolest! For a 5.3 in that thing, you really need to be thinking smaller on the cam. At the same time, it's no suburban. That larger cam will have ptv issues, and the smaller one will be right on the edge. For 6500 max rpm, you will want power to peak right near 6000, which is actually low for a LS, not high. Again, all this points to a smaller cam being a better match.

I would look at something like 224/224-110+4. An old, basic cam from the early LS days. Good torque, decent power, some muscle to the idle. Should peak somewhere around 5800-6000 and then carry to 6500 or even further with the valvetrain set up for it.

Run it with .041 head gaskets, and to push it just a little further, mill those heads to 59cc's. I think you'd be thrilled with that combination.

G Atsma

That will put it at 9.93:1, assuming stock 8cc dish pistons and the above specs.
Who has .041 head gaskets? I usually see .040.

Darth_V8r

iTrader: (4)

fel pro, cometic. Both have a .041 MLS.

spanks13

iTrader: (5)

Grandma's car checking in.

Get the lil chopper from cammotion.

https://cammotion.com/camshafts/litt...222-232-108-3/

LewisL230

The compression would actually be a little higher as the LC9 is a flat top motor. I’ve been talking to summit and they recommended the 8704 cam.

SUM-8704 is 227/239 .551/.551 108LSA

They said that paired with the 3.73 gear and a 3500 stall converter it would be a great strip setup that would also be good for short trips on the street.

This is the car in question. This is as I got it. It will be a work in progress over the next little while.

G Atsma

Right! The LC9 already has 9.9:1 compression. Don't forget your heads (799/243) have larger chambers than the 706/862's of Gen III engines.

Darth_V8r

iTrader: (4)

Yeah I was pretty sure it was a flat top. The cam summit recommended is going to be close, honestly, on PTV. Be sure to check it and read up on how to flycut. With dished pistons it would fit fine for sure. If you go to a thinner gasket and mill to 60cc, that'll get you to 10.8, which will help almost any cam you pick to perform better.