I work at a GM dealer so I can get a pretty good discount on GMPP parts. I was wondering what kind of advantage the L-69 cam would make? Also, what did the L-69 cars run stock in say 1984? Whats the big differences between the LG4 and L69? I heard they run high 14's-low 15's. Please let me know, as I finally have the money to do the cam and fix my leaky timing cover. THX in advance guys and gals.

 

GTA,

Personally, I wouldn't bother. The difference in cam profile will not make the effort worth the result. GM is notorious for extremely conservative cam profiles, since they want their engines to run forever with no headaches. The L-69 is no different. I would believe that a GMPP LT4 hot cam, LT4 production ca, or even the ZZ3 cam would do much better for you. Of course, each of these would require better springs (and probably head machining). The problem you may experience is that the stock heads don't respond well to extra lift after a point, so a lot of cam lift might not help unless the ports are opened up a bit.

 

Thanks for letting me know. But....what cam do you guys recommend i should put in the little wee-05? I want to go with a Compucam that will work with my computer system. I had the Comp XE262 in there a while back, and it pulled like a bat outta hell but it just didnt idle at all. I want something from say 1000-5000rpm. I know everyone is going to say "just build a 350", but I want to see how quick I can get this thing going. Id love to run low 15's eventually. But I need to get the cam situation under control. THX

 

I'm not a hotrodder by any means, but I did want my LG4 (85 IROC) to do a bitter better, so along with tweaking the carb with a B hanger and DR secondary metering rods (AV tension and KN filter), I also threw in a Summit cam, #SUM-K1102, and an Edelbrock intake manifold, #EDL-3701. Those, along with the L69 exhaust--manifolds, y-pipe, 4-bolt cat, and intermediate pipe, really awakened the boy.

JamesC

 

IMHO it would be a waste to go to all that trouble for the L69 cam, even though in my year (83) with a 5-speed, they ran about 15.2 or so off the showroom floor, and are quite easy to get into the 14s with tuning and weight loss.

I have a XM264HR-12 in my 305 right now, with some 186 heads and Edelbrock TES on it, and everything else stock (carb, intake, and all smog equipment), it passed CA emissions testing and then went to the chassis dyno and did 214 RWHP which works out to about 260-265 crank HP... enough to thoroughly roast most L98 cars, as verified on the street

The Comp XE cams are much better designs than the Crane ones. You could use a Comp XE256H, it's got the superior design like the 262 but should idle better. Even better would be a XE262H-12 which is 112° lobe separation for fuel injection applications like 85-86 TPI instead of 110° on the standard XE262.

The LG4 block, crank, heads, and intake are the same as the L69. Everything else is different. The L69 got X rods instead of 305 rods; flat-top pistons instead of dished, which gives about 9.3:1 CR instead of 8.5; the better cam; electric fan instead of clutch fan, which doesn't sound like much, but is good for about 8 HP less parasitic loss; different carb; much bigger exhaust all the way from the heads to the street, probably 15-20 HP right there alone; 3.73 gears; and in my year, the fiberglass hood. All added up, the difference in HP rating from the factory was 45 HP That's alot, roughly a 33% improvement using the same heads, which should give you some idea of how much room the LG4 has for improvement.

Get that exhaust off of there. Put on some application-specific headers such as TES or Dynomax or whatever, but DO NOT get anything specific to the LG4!!! Get a whole system, from heads to street, for something like a 89 350 with single cat. Any piece that fits LG4 will retain the restriction of the tiny tubing the LG4 came with, which will completely eliminate the benefit of changing the exhaust in the first place.

 

Thank you all for replying to my post. I do have a complete 350 in my garage, but I want to be different and build a nice little 305 for the street. My goal is to eventually get the car to run mid 14's. But I know that is not possible without getting rid of those 8.5 to 1 pistons. I was looking in my Next Generation book at cams and the XE256 looks to be right in the RPM range I want. After the cam, i will for sure do the entire exhaust.


My problem is when it comes to be rebuild time, I cant find any place that has 305 pistons above 8.5 to 1. I want to go around 9.4 to 9.8 to 1. Also, if I increase compression, will the XE256 work okay or will it need more? I know of a guy out here that deals in nothing but GTA and Z28 parts. So I think I'll talk to him one of these days and get the 3" exhaust from the manifolds back, finished off by a Flowmaster. I will also pick up a set of headers. How are the Hooker shorty headers for 139.99 in Summit? Will those work okay?

Any more info will be greatly appreciated.

 

As you can see from my sig, I "built" a 305 for the street. But, I didn't touch the shortblock (unless you consider the oil pump and cam to be part of the shortblock). I worked the 305 over only because I figured I'd get more power out of the money spent than I would if I spent the same money on a 350 (I still maintain that position, unless some "sweetheart" 350 deal is involved). Mine already had flattops for a 9.5:1 CR, by the way.

You can get flattop 305 pistons, hypereutectic or cast, from partsamerica.com (look at '85-'87 pistons, not '83). But, before I would replace pistons in a 305, I'd go the 350 route. "Different" is only worth so much, and nothing at all when you're looking at taillights all the time. I think you'd find that a 350 is more than sweet for a street engine, and showing others your taillights is "different" enough.

Also, you might want to take a look at the Crane PowerMax cams for computer cars (I'm sure RB isn't including them in his assessment). I am simply amazed at the way mine runs. If you're going to do a cam, at least go with an aftermarket performance cam rather than a factory cam (even one you can get at a discount).

Finally, I don't think you want the Hooker Comp shorties (the $140 ones from Summit). The don't come with a y-pipe and none is available for them - You're looking at a custom piece, and unless you know someone at a muffler shop who can work off the clock, you're going to spend more for those headers and a custom y-pipe than you are on the Super Comp shorties 2055's that come with the y-pipe that has the 3" cat connection RB wants you to get. I don't think they are in the Summit paper catalog, but go to their website and search on HOK-2055 and you'll see them listed.