Originally Posted by sofakingdom

No, no one. Ever.

Seriously...

The choke points in that setup are, in the order they should be fixed:

1. Exhaust
2. Cam
3. Air cleaner
4. Electric fan
5. Gears
6. Heads
7. Converter (if it's an auto)

Notice that at NO POINT did I mention the carb, intake, or ignition system; hacking off any emissions eqpt; aftermarket "chips"; add-on ignition boxes; or other typical wastes of money. The reason those are wastes of money, is that THEY ARE NOT THE THINGS LIMITING THE CAR'S PERFORMANCE. Note also that I said "car", not "engine"; as not all of the things that make those slow, are under the hood.

1. Exhaust - needs to be replaced, as an entire unit. Every piece from the heads to the back bumper. The replacement MUST NOT be designed to fit LG4; because if it is, it will PRESERVE the LG4 exhaust bottleneck, namely, the itty bitty Y-pipe. Get one of the quality brands of headers SPECIFICALLY for one of these cars, BUT NOT for the LG4; get the ones for a TPI 350. Get a high-flow cat such as a Catco from Summit, and your choice of cat-back. All of this for something like 89 TPI 350 without G92 (single-cat setup). This will retain emissions legality (except for the EFE valve).

2. Look at cams in the 210 - 215 degree @ .050" range on the intake, with a larger exhaust lobe. Comp's XE256 and XE262 are known to work well. Crane has cams of somewhat similar specs that also give good results; I think it's the Energizer 272 but I could be wrong. Lunati's new Voodoo series is the right design for this, and may have something in the right duration range for it. Whatever cam you pick, avoid choosing it based on "sound"; any cam that "sounds" "good" will probably be too much for the rest of the engine and car. Replace the valve springs and their hardware, and the timing set, along with the cam. DO NOT try to use a modern cam under stock springs; you'll probably break something.

3. Get a dual-snorkel one from L69. This will give several HP over a typical open element, since it will give the motor cold (dense) air instead of hot, thin underhood air.

4. If your car has a clutch fan, it uses a good solid 12 HP just to run the fan. An electric fan will give you back those HP. Watch the classifieds on this site for a used fan setup.

5. Those cars were always the "sacrificial lambs" to CAFE in the V8 F-body product lineup. At the time they were new, the people who bought them were looking for the "image", not the "substance", of performance. Since anybody that was buying a new car and was seriously interested in performance avoided those like the plague, I guess GM figured they could nut them as much as they wanted to get their fuel mileage up, and nobody that bought them would care (might even like them better in fact, if they were cheaper to drive; no matter how slow). So they always got crappy gears. The best they ever got, standard, was 3.23; and most years they got 2.73 or the like. 3.42 or 3.73 makes an AMAZING difference to a 2.73 car. If yours already has 3.23s, it's not quite so urgent; but once you get the motor to breathe, it will benefit from 3.73s. In stock condition though, 3.73s will force the engine RPM so quickly up into a range where the motor has no power, that it won't really be any faster than stock; even though it will feel like it has this huge launch off the line.

6. The heads themselves are fine, entirely adequate for 305; except that they can use some porting, and larger intake valves. There is a great deal of HP available here.

7. This is like gears. The stock converter pins the motor to a very low RPM range, especially from a stop. Once you get it to where the motor has some higher-RPM power, letting it rev up when you punch it will give it a much harder "leave".


I cannot emphasize enough, RESIST THE TEMPTATION to un-bolt and re-bolt big shiny things that sit up there where everybody can see them, on top of the motor. There's an old saying you'll hear at the race track, from the people who WIN: "Chrome don't bring the money home". People who spend their limited cash on "dress-up" are choosing the path to a slow expensive car that loses races.

The parts that produce performance are INVISIBLE. Don't let that discourage you from doing the right thing. Spending your money on things you can "see", will produce little or no results; except maybe, the car will be lighter, because the driver's wallet will be thinner.

Which reminds me of another whole set of things you can do to make the CAR faster; and that is, lose weight. I don't advise hacking stuff off; few things make me puke as bad as all the people who hack off their AC, for example. But, any time you replace something, make an effort to get something lighter in its place. For example, a "mini-starter", a plastic/aluminum radiator instead of copper/brass, an aluminum drive shaft, lighter wheels, lighter flywheel if it's a 5-speed, aluminum bumper support to replace the steel one, the 82-83 "composite" hood, etc. etc. etc. You can shave an easy hundred pounds off of it that way, maybe more.

Originally Posted by five7kid

Depending upon the cam, in the 275-300 "gross" flywheel range. "Net" flywheel would be in the 200-240 range.

Originally Posted by five7kid

"San Leandro, CA" - I assume you have emissions testing and inspection. If that's the case, the only CA emissions legal headers for carb'd cars are the Edelbrock TES. The L69 headers are much better than the LG4 type, but if you have an LG4, you need an L69 EFE valve and L69 cat & cat-back to get the most out of it. However, an alert inspector may fail you for not having the headers and cat for your particular car.

Originally Posted by david chambers

compression beyond 8.6-1 REQUIRES better gas than 87 octane my fresh LB9 with 9.6-1 compression will only run on 92 or better gas.if you can afford avgas it is 100 octane you will notice avgas has NO ethanol .as ethanol destroys aluminum it should be avoided at ALL costs

Originally Posted by david chambers

compression beyond 8.6-1 REQUIRES better gas than 87 octane my fresh LB9 with 9.6-1 compression will only run on 92 or better gas.if you can afford avgas it is 100 octane you will notice avgas has NO ethanol .as ethanol destroys aluminum it should be avoided at ALL costs

Originally Posted by speedfreak180

well i agree with you five7kid. because that plug come from the sylinoid from the cowl induction but what does that plug into. and second how hard is it to swap out carbs wanting to go to an edlebrock but mine has 3 plugs that plugs into the factory carb. the edlebrock doesn't so how do i fix or get around this problem.

Originally Posted by speedfreak180

can anyone tell me what this plugs into.

Originally Posted by five7kid

Could you explain why you posted here?

BTW, you aren't exempt.

Originally Posted by Mike85TALimited

Just wondering if true dual exhaust was an option to put on an 85 with the LG4 to remove airflow restrictions, or if the best bet is to just cut off the Y pipe entirely, since that seems to be the major bottleneck in the system.



Yes, I am. My car is no longer required to take emissions tests.

Originally Posted by Mike85TALimited

Just wondering if true dual exhaust was an option to put on an 85 with the LG4 to remove airflow restrictions, or if the best bet is to just cut off the Y pipe entirely, since that seems to be the major bottleneck in the system.



Yes, I am. My car is no longer required to take emissions tests.

Originally Posted by five7kid

BTW, you aren't exempt.

Originally Posted by Mike85TALimited

Yes, I am. My car is no longer required to take emissions tests.

Originally Posted by 87WS6

Just fair warning. You aren't except from Federal emissions laws, just emissions testing.

Originally Posted by www.epa.state.il.us

The following vehicles are exempt from vehicle emissions tests:
...
Vehicles of model year 1995 or before that were in compliance with the Illinois Vehicle Emissions Inspection Law on February 1, 2007;
...