Please do not mention 350, I dont want a war. I was wondering wat kind of 1/4 miles to expect with this set up and what kind of hp/tq to expect 1987 chevy camaro sc carbed 305 holley remanufactured cc q jet carb edelbrock perfromer intake manifold pacesetter 305 headers edelbrock 14in open element air cleaner high flow cat and flowmaster dual outlet muffler holley fuel pump. Next question is, what would be my next step as far as performance goes besides nos.

A couple of years ago I had an LG4 in my car. Here's what I had:
Edelbrock Preformer intake
Edelbrock 500 cfm vac secondary carb
Hooker shorties
Hooker catback
5 speed and drag radials with a 3.23 posi rear.
Sportline spings, which probably are worse than old stock springs

At the time I didn't know how to set the timing correctly and had it retarded too much.

But I ended up running a 15.7. That combo should have netted me low 15's I would think. Sorry, but I can't really tell you what kind of hp/tq numbers this should make *shrug*.

And for performance, I wouldn't do too much to the motor. Save up for a motor with more displacement (I know you don't want to hear that). Roller rockers would gain you some horsepower. If you don't have a posi rear end, get one and throw a set of gears in it.

I'd guess high 15s if not low 16s. Those gears are gonna hurt you and those are pretty mild mods.

Hey DLV555, I have a 89 L03 what have you done to yours. What effect will upping my 2.73 posi have. I don't drag it, just want more seat of the pants hp from daily driver. I welcome any comments from anyone

I also have an 89 L03. I've run both 3.42's and 3.23's behind it. Both ratios were a HUGE improvement over the 2.73's it had originally. I would've kept the 3.42's under it, but that rear was an one-legger with drum brakes. The 3.23 rear is a 91 posi/disc, and pulls way better than the original gears. If you're on a budget, you can find either ratio in V6 f-bodies at the junkyards. They probably won't be posi, but they'll have good ratios for dirt cheap.

'86 LG4, feedback Q-jet, bone stock engine, L98 donor exhaust system, 3.73 gears:
15.70 @ 87 mph in 95 degree heat.

So in answer to your question of next step, I'd have to say......gears. If buying new and staying with a relatively torquey stock engine, I'd prefer 3.42's over 3.73's for a daily driver. Mine were a junkyard find.

Going from 2.73s to 3.42s made a drastic difference in daily driving. The car has more guts at every RPM. It also got me 3 tenths in the 8th. It genereally feels more "spirited". So it's better, but in the end a stock L03 still only has so much grunt in it.

See the car in my sig below. It is routinely beating high 14 second cars, I guestamate a 14.7 @ 90mph, hopefully I'll have some track times to back that up before the end of the year. Converter and gears will make a new machine out of anything.

You've got headers and an exhaust, and a good breathing top-end, the next step in the motor would be a cam. Either the cam in my sig below, or something slightly larger will surely wake that motor up.

Flat-top piston 4-bolt main 305 (10.5:1 compression, Balanced rotating assembly, stock forged crank, stock "X" rods )
Ported 14022601 heads (1.94/1.60" valves)
Crane 274H06 hydraulic camshaft (1.6:1 roller rockers)
Edelbrock performer RPM intake port matched to the heads and a Felpro 1105.
Marine 2" bore TBI unit @ 30 psi with 68# injectors and a Marine TBI-Carb intake adapter.
1 3/4" primary headers into 3.5" collectors and dual 2.5" exhaust
2,800 rpm stalled 700r4
3.08 posi-traction 14 bolt
5,300 lbs G20 van

End result was 15.3s @ 95 mph all night long.

This is what I was thinking asfar as next step, Now I just haft to research and see which one is best for my application, Street DD and maybe strip every couple months.

Also what gears should I go with? Will a posi fit in my 10 bolt right?

There's really no info there.. you have some sort of holly carb cfm unknown, a 305 with unknown heads, cam, and compression, a stock replacement intake manifold (performer), you do have the exhaust done which is good.. what transmission is in back of this and what gears? Yes a posi unit will fit in the housing, no difference there.

wow that is high mph for a van with a 305 and 3.08 gear

The other guys didnt have much trouble answering me......Stock heads, stock cam, dont know about compression, 700r4 tranny, 2.73 gears.


I think I am going to try and get a transgo shift kit, then do the posi unit I just dont know what size gears to go with. After those are done im gonna go into looking at a cam and either have these heads ported or try to find some sort of aftermarket 305 heads.

I know, it was definately a fun, high winding engine that made good torque, even down low. The main points were GREAT flowing heads, high compression, mild camshaft, and the rest of the combination matched well. I would bring it up to 1/2 throttle and 2,400 rpm, ease it out of the hole, then hammer down. Never could beat a 2.28s 60' time. With the hammer down, I would flat-shift @ 60 mph (6,500rpm) and then proceed down the track to cross the traps at 5,600ish RPM in 2nd. It would pull above 6,500 rpm, but I got nervous and had the rev-limiter set at 6,600 rpm. I just did not trust the factory "X" rod castings much above that. The valvetrain was also done there. If I had played around with the 305 more, I would have stepped back to the next smaller cam, although I would have gone roller.

Since your car is mostly going to be a daily driven street machine, I'd say you oughta go with 3.42's. 3.73's are a bit much for a daily driver. 3.23's work pretty good behind a 350 because of the extra torque, but 3.42's are ideal for a 305. They'll give you plenty of get up and go off the line, and they still work just fine on the freeway with a 700r4. In fact, 3.42 is the ratio GM used in the 305 cars that got the G92 performance option. Probably the best all around ratio you're going to find.

I disagree, 3.73's work well on the street. The 700R4 has a pretty generous overdrive, I pull about 2500rpm at 70mph. Not ideal for gas mileage, but nobody drives a V8 Camaro for that anyways. I guess it depends on what you want out of the car, if it is your only car, then maybe you want to focus more on mileage than performance. I think for the 1-2 mpg you may sacrifice going to 3.73's will be worth it every time you smack the throttle and you get a huge smile on your face. The 305 with a good build will really like those gears, and they are well suited to the 1/4 mile strip.

Pat Hall or anyone, if I get 3.42 gears out of a junkyard V6 f-body can I still use the posi that's on my 2.73's

If you were going through all the trouble to rebuild the differential it would make sense to just get new gears while your at it too.. They should fit on the carrier though, and you could probably find a cheap set over www.LS1.com since they are the factory gear ratio on 6 speed cars.. not sure about autos, but most people swap up to 4.10s and sell their 3.42s cheap..

Good to know, thanks

The 3.42 ratio calls for a 3 series carrier, and your 2.73 posi unit is a 2 series carrier. You can still use your 2 series carrier if you use a ring gear spacer when you install the 3.42's. Some guys don't like to use the spacers, but there's an equal amount of people out there who've used them without any issues. Normally I'd recommend just getting a 3 series posi, but if your 2 series unit is in good working order, it'd be way cheaper to use the ring gear spacer vs. buying another posi unit. If you're set on putting used gears in, I'd say probably 99 percent of the manual trans, V6 f-bodies got the 3.42 ratio. Some of the auto trans, V6 cars might have them as well, but most of them that I've seen in the yards are usually 3.23 ratio. 89RsPower has a point about running used gears. You can do it, but there's about a 50/50 shot whether they'll be quiet or not. Once a pattern is worn into a set of gears, it's really hard to get the exact same contact pattern when you put them in another rearend. Getting them bead blasted before installation helps. Also make sure whoever installs them is well experienced in setting up rearend gears.

ALOT of 2.8 V6 powered S10s and S10 Blazers had 3.73 gears and posi. 4 cylinder Astro Vans were commonly equipped with 4.10s and a posi.

And, on top of all that, when you change out a gear, you need an "install kit" (or all those bearings and whatnot bought separately); which is more $$$.

Gears are less than $200.

By the time you buy a spacer, a kit, all the fluids and whatever other supplies and materials, tools if you don't have them or pay somebody who does; you'll have SO MUCH MONEY in this that it would be bald-faced stupid to run used gears, anyway. As cheeep as new gears are, used ones aren't worth the risk IMO. So a truck rear wouldn't be an economically sensible way to go.

However, if you get a rear for one of these cars, with the gear you want already in it and set up, then you can just jam your posi carrier and a spacer in it WITHOUT DISTURBING THE GEARS; basically risk-free, and FAR FAR cheaper. That's the better way to go, since rears out of 6-cyl cars (even though they entirely forget their lowly origin the instant the bolts are loosened) are typically dirt-cheap and plentiful, compared to the REALLY desirable ones like 90-92 G92 disc ones or something.

I have to agree with sofakingdom. I put used gears in my Firebird and they work great and everything, but they're noisy. I got them for a great deal and figured I give them a shot, but oh well...lesson learned. If you don't set the gears up with the exact same pattern they had in their original installation, they whine. I'd save and buy the new gears, you'll be glad you did. Not to mention it helps your situation since they make series 3 gears (3.23 and up) that will fit series 2 carriers (3.08 and down).