Please help with some general questions: Have 1987 LG4 T/A. I live in Massachusetts where the smog laws are comparable with California's. I would like to increase the engine performance on the 305 motor that is at the moment completly stock. Would you give me some suggestions on performance parts/add-ons, or any custom parts to achieve more power while staying within the states legal regulations ?? Would appreciate any advice or comments you might have to offer. The 305 runs very strong and would like to keep with the car. A 350 is an option in the far future but that would also require the same as above. Any comments on a future 350 that would bolt right in would be great for future reference also. As for right now I have to stick with the LG4. Thanks a 1,000,000 !!!!
Fakeyankee.

 

The parts that limit performance on an LG4 are single snorkel air cleaner, cam, heads, and exhaust.

Anything after the cat is non-emissions, so a 3" cat-back is in order.

A factory dual snorkel air cleaner will retain the thermovac system, so that shouldn't be an emissions inspection issue.

You can port the heads and install 1.94" intake valves with zero visibility to the Smog *****. That will yield a nice performance boost.

Computer-compatible cams are available from Crane & Comp. Again, zero visibility.

Technically, the exhaust has to have been designed to replace the factory parts. For practical purposes, they're going to look for A.I.R. and a cat in the factory location. So, Hooker 2055 headers, a direct-fit '86-'90 TPI single-cat application 3" cat (like Catco Summit p/n CAT-9118), with a cat-back for same application will be a great performance improvement and shouldn't raise too many inspector eyebrows.

 

Five7kid, Thanks for the info. Unlike Cal. Smog ****'s, Mass. doesn't give the motor a total go through except the minor safety inspection: horn, lights, turn signals, tires, ball joints, and seat belts. They stick the magic wand in the tail end exhaust, run the car on some type of dyno machine through different speeds, and if the numbers come out under state regs, they slap a sticker on til the next year ! Hear Cal.'s laws are alot worse. What would be a ball park figure for the modifications you had mentioned ??? Thanks !!
Fakeyankee.

 

Even though your a yankee's fan i'll help you out.

I have a 1992 ws-6 Trans am 350TPI, not modded much at time of inspection.. K&N filter that clamps to throttle body, flowmaster,ported intake and airfoil, and (had) gutted dual cats. The car has 150K and still passed just fine on the dyno test. Unless your car is running really bad, you wont have a problem even without cats. My advice, get a K&N filter, cold air or just open, headers,3inch cat back and gut the cat if you so desire, just make sure you keep the shell on the car. Things like cams, porting etc. arent going to make you fail per se, as long as you have a proper tune. Just my .02 cents. Oh and another thing, if you have disc rear brakes, make sure the rears WORK. Nothing like running the car up to 50mph on the dyno and not being able to slow it down LOL.

 

Also wanted to add, my friend had a 6 banger firebird and put in a 70's vintage 350 carb motor, with headers and no smog. Tuned it right and it passed no problem. I guess the smog guys can't tell the difference between TBI and Carb.

 

Having moved from California to Colorado, I'd say Colorado is worse. Only exception is that California checked the physical function of the EGR valve by applying a vacuum to it, while Colorado allows the enhanced dyno to determine if the system is working (I understand parts of CA have the dyno now). The visual inspections otherwise are about the same rigor.

Anyway, you said "comparable with California's", so I assumed a rigorous visual. Without that, then good tune can compensate for lack of equipment. But, your best bet to pass sniffer is still to retain at least the cat, and A.I.R. system to the cat (A.I.R. to the headers is optional, since it only sends air there when the engine is cold).

Cost? Headers range from $200-$450, with y-pipe, uncoated. The Hookers are about $350. Cat is $117 from Summit, cat-backs run $200-$350 or so.

Dual snorkel air cleaners are getting harder to find, figure on at least $150 for a full setup.

Roller cams go for about $250, but are worth it if you already have one, in my opinion. A cam will make you fail if you go too wild with it, but the computer-compatible types won't have that issue.

Porting can get expensive if you pay someone to do it. If you do it yourself, you'll need a die grinder (and good-capacity air compressor if an air die grinder) and a $40 porting kit. Larger valves cost about $5-10 each, figure on about $40-80 on top of a $150 valve job to get the seats cut for the larger valves. Valve springs should be replaced to handle the new cam, those are typically $50-$150 a set. The rocker studs are press-in from the factory, they should be replaced with screw-in to handle the extra load - another $50-100. An alternative is to get World S/R Torquer 305 heads and port them - already have larger valves, good springs, and screw-in studs.

Another good idea if you put in a higher-reving cam is to get a higher stall torque converter to get the engine into its powerband earlier.

 

Hey mhaskell....... For your info. I'm a Die Hard Red Sox fan. I live south of you in Taunton. Actually, i'm from Wyoming in the Rockie Mountain area hence the name Fake-Yankee. As for the Yankee's......You know how us Red Sox fans feel about them !!! Thanks a bunch for the info. !!! And thanks to you too Five7Kid !!! Really appreciate all your time and effort in answering my questions. I bought this 87 T/A from some kid for $400 bucks. Guess his mom told him to get rid of it as he went through some jersey barriers, slingshotting from one side to the other up on 93....... your area mhaskell. Anyway, the body damage was minimal and eventhough the motor has high miles, it still runs real strong and fires right up !!!! I have time on my hands and decided that this would be a great project car. What about bolting in a 350 in the future ?? What would be a good 350 and engine year to bolt right into with the same smog issues to deal with ???? mhaskell, know of any good boneyards to pick up a descent 350 in our area ???? Thanks again !!!
Fakeyankee.

 

I'm in Boston for school, born and raised in Rehoboth however,right next door. Get in touch with the guys over at http://www.nefbody.cjb.net/ It was started by my buddy Matt, Tell him haskell sent you. They have meetings often at the swansea mall and various car shows. As far as getting a 350 block, I know of a complete 350 and L-98 heads for sale locally. Let me know what you need and what you have for money to spend and I'll ask around. If you need a flowmaster system, I am taking mine off within a week or so along with my dual Cat set-up. I personally have various parts for sale, as do friends of mine. If you want to talk online my aim name is mdhaskell ,later.