Hi everybody,

Not too long ago, I picked up a 1986 Trans Am with the LG4 engine. After driving it a bit, it now has 28,016 miles on it. Other than a few minor issues from being so old and just sitting most of its life, it is in awesome shape.

And, it's slow. Really slow. I believe my wife's 4 cylinder Equinox can take it light to light. I am frequently outclassed by Toyota Prii on the highway. I have been a muscle car fan since my dad and I first built a Firebird for my 16th birthday, a long, long time ago.

Sure, it's cool driving around in a well kept classic, but the thrill is not there. So, should I:
1. Keep the car stock, and just enjoy it as it is
2. Drop in a bigger cam and maybe some HO heads, plus full exhaust to try and keep it somewhat true to its roots.
3. Yank that boat anchor out, toss it into a dusty corner of the garage with a tarp, and drop in a mild street engine (275-300 hp)
4. Sell it as an unmolested 35 year old survivor of a model that is generally not sought after, and try to buy a different F-Body that may not be as nice, but already has at least decent performance.

I don't intend to race it, but I also hate having to rely on the kindness of strangers to merge onto the highway.

What are your thought?
Tony

 

So my 2 cents. Unmolested examples are getting harder to find and are increasing in value (lots or little depending on who you listen to). I started with a junkyard dog and I like fast cars so I'm less concerned with keeping it original. Having said that, I wouldn't mind a clean original car as a second one but again try to find one and at a reasonable price. So ask yourself if you keep reading the History/Originality section or the Performance sections. Spending money on that motor will not let you keep up with any of today's cars, period. That's what started me own a long expensive road. The safest bet would be to pull the motor as you've suggested and store it. Put in a crate 5.7 with 300-350 hp. Everything bolts up and you don't need to molest the car. Plus you get a quick car, that looks stock and you can return it to bone stock down the road.

 

1. Sure, you can always buy another car if you want to go faster.
2. Not a chance in hell. Waste of effort for a 305 to just decrease value.
3. Probably also decreases value. If you never sell then this option is just fine.
4. Why not keep it and do this too? See #1.

 

pull out the 305 and replace with a 350-383,rejet carb to suit the replacement engine Also rear gear(if the usual 2.77) should be replaced with 3.27 or 3.45. I don't think the original engine would hold much value,so probably sell that tosomeone who wants a nice replacement '86 305.

 

I wouldn't hesitate to modify it for increased performance. I like thirdgens (which is why I'm here), but far too many people think these cars are a goldmine. They're simply not. You don't have to hack the car up. Do some upgrades like rearend gears, torque converter, maybe exhaust upgrade...

 

That car is pretty low miles, being able to preserve its stockness would be a consideration for me. I say pull the engine whole and prep it for long term storage. Dropping in a complete replacement 350 based sbc will give you as much power as the rest of the stock drivetrain can handle, and should be a very straightforward swap. You'll get your increased performance and the car can still be returned to factory if you take your time to do it right.

 

I think at the end of the day it comes down to the financial math. What's the cheapest route to get the car where you want it. How do you want it to look? How do you want it to drive? What can you do yourself? What will you pay to have someone else do it? What's already done on your current car? (paint, body, interior???) If you sell and buy a beater, how much to get it where you want it?

Everyone throws around terms like "cut up" or "hack", with regard to modding these cars, but I think that's kinda like a knee jerk reaction. So many of us Thirdgen fans lived through the days where 17 year old kids would buy a nice clean IROC or TA, yank the TPI, yank the AC, drop in a thrown together carbed 350, and a TH350, with some big old tires and think they someone "saved" the car. Nowadays however, SOOO many people are modding these cars, and many are doing them justice. More are getting saved than destroyed. There are certainly a few low mile, high option cars that I think do deserve to be preserved, but outside of those cars, I say have fun! I've always felt like if you could ASK the car if it was happy, what would it say? If it's happy.....then who cares!?!?

 

You can get the 305 up to 325-350 hp fairly easily. Personally I would start with dyno don headers and y-pipe and a 3" catback. Make sure the tune up is in good shape and the Q-Jet is working correctly. Etec170 heads milled 0.030" woke even the 305 Vortec in my 99 Tahoe up. Vortec 305 heads flow alot better than HO 305 heads which incedentally your LG4 already has.

 

Thanks for all of the replies, guys. I am thinking about doing a gear swap in the rear end and making sure that the engine and carb are all tuned up correctly. Full exhaust is already on the radar.

I'll probably keep it stock other than that. The car is in super shape as it is. I think I got most of my street racing out of my system years ago, but there's always that good feeling of having the power, even if you don't use it. What I need to do is learn more about the electronic carb and distributor. I can make this car a nice cruiser instead of a ground-pounder.

Besides, my wife always thinks I am going to expire from heat and old age every time I crawl under that car to work on it...

Thing is, I really like wrenching on cars. I told my older son, a few years ago, that we could go get an old muscle or pony car and do a build up and restoration on it, then he would have a cool car he worked on when he gets his license. He was not interested. My youngest son thought it was a great idea. When I asked him if he had a car in mind, he said a Tesla.

I can't win!

 

This topic is a polarizing one on this site, as you might imagine. My thoughts are that if the car is a low-mileage, original example in very good condition, you'd do well to keep it that way. If you have a need for speed, you might want to think about finding a more-suitable 3rd gen (a roller, or at least one already extensively modified away from original) for your project.

How much stock do you place on keeping your low-mileage car all-original?
Are you at all concerned about such cars' value increasing over time?
Do you expect to keep the car, or do you see possibly parting with it at some point in the future?
Do you understand that in order to bring that car's performance up to current-day standards, you'll be looking at significant modifications (not just to the engine) and expense and, and if you decide to go that route, who will do the work?
Realize that these old cars are only original once.

As always, it's your car to do with as you choose. GL going forward.

 

I feel for ya.
A friend of mine got a '70 Chevelle for a father-son project, only his son had no interest. He ended up selling the car...

 

Put 3.73 gears in it and it will make it more fun. LG4 with 3.23 gears just doesn't have the grunt.

 

I had an L03 very similar power to your LG4. I put 3.73 gears, posi-unit, S10 torque converter, shift kit, 3 in exhaust.. It made it a lot more peppy and that may be enough for you. Eventually put in a mild 350 and that's what I would suggest to you. Keep it looking stockish and spring for a 350. Huge difference

 

I appreciate everybody's input. This is actually my 6th Firebird, in my somewhat long list of "high performance" cars I've owned. I plan to keep this one, I think. It will be strictly a good weather car, and I doubt I'll put a bunch of miles on it. My younger brother says he's going to buy me a 3.55 gear kit from Summit for Christmas. He also has access to a lift when I want to do the exhaust. I'll probably stick with that, and just have a nice car that is a little zippy. It's probably why I bought this one instead of a higher mileage, faster one. I just wasn't aware that it would be this slow at the time!

I'll always be fighting the itch to do some wrenching on it. It's what I do to relax. Most of my knowledge is pre-computer, though. I need to go through the stickies in the Carburetor section.

 

Thumbs up on that. Changing the gears will make a huge difference in the way it feels. I've decided to enjoy my Z28 for what it is; it will never be fast by today's standards and that's ok. For me it's mostly about nostalgia and working on it as a hobby. It's just fun to own a third gen, especially one as nice as yours.

 

Keep your upgrades to stock looking upgrades if you want it look OE and not pull the motor. The entire exhaust (including the cat if you can)from the manifold to the tailpipe should be replaced with a freer flowing system. Maybe some new heads with roller rockers 1.6 rocker arms and a intake manifold. That with a posi 3.23/3.73 rear end could give you the driving experience desired and leave the numbers matching engine block in the car. If you are willing to replace the cam I would convert to a roller camshaft for better performance and no worries about the lack of zinc in modern motor oils.

Or, put a late 80’s 350 in it with the 1pc rear main seal and roller camshaft. You could reuse all the accessories and no one would know until you buried the throttle that it wasn’t stock anymore.

Good luck with whatever road you choose with your car and please let us know what you decide!!

 

My 89 Iroc was a 350TPI automatic with 2.77 gears. Swapped to a 3.27. Then swapped in a higher stall torque converter. The converter made more of a difference than the gears! Of course it was several months after the gears, and of course, they were already installed, so it's not apples to apples. Point is, Don't overlook all that low rpm slop you have to deal with on the stock converter. I think mine was a 2300 stall, and it slipped right up there into the beginning of the power band! I think a properly built and set up automatic is almost a must for any older car with a desire to be "faster" in this modern day.

...LOL....or of course a manual swap!!!!

 

About that 3.55 gear... you might want to rethink that. It would be quite a bit easier to recalibrate the speedometer if you stick with a gear ratio that was available from the factory.

 

Exhaust from the manifolda back won't do much with those terrible manifolds still on the car. The TPI engines with those manifolds and single cat lost 25 hp compared to the better larger outlet manifolds and the dual cat setup.

 

Good point.

Since I will most likely be keeping converter lockup, I might go with the 3.73 gears. I anticipate some highway miles once in a while, but most of it will be city driving. So, maybe my gas mileage won't suffer TOO much! I would like my speedo to be accurate so that the miles are correct.

 

You can get a lock-up torque converter with a higher stall speed. I have a 2000 RPM stall lock-up converter in my '83...

 

Speedo recalibration is a piece o cake. (apart from gears being in stock or not) I wouldn't get too concerned about that. Search my userID and the phrase "smuc", I've published how it works and how to calculate the gears several times.

IMO 28k miles is too many to be considered a "pristine" "survivor", on that kind of a car. It's past the point where preserving its "originality" has any value at all. If it was some kind of premium level model, it might be a different matter; but a LG4 car, ... no way. I would not hesitate to put a better motor in that. Nobody wants to "remember" that POS, or is going to get all nostalgic about how they had one, and they loved it so much because it was so slow, and is going to pay you EXTRA for keeping it. That's just fantasy land.

That said, I would also NOT just cut the car up and hack it to bits. I would take the approach of a motor replacement that's as factory-like as possible while eliminating the slowness of the LG4. First thing that's gotta go, under the hood, is the exhaust, EVERY SINGLE PIECE from the heads to the street. I'd get the best quality chassis-specific (NOT "universal") headers possible, stainless, and ceramic coated, and NOT for LG4 since anything you buy that's compatible with the rest of the LG4 exhaust will preserve that setup's bottleneck (the 2¼" Y-pipe); a new high-flow cat; and the cat-back of your choice. When I had a 400 in my car I had SLP headers, a 4-bolt L69 cat (my car was a L69 to begin with), and the Hooker cat-back. I got some other turndowns for the "tips" because the Hooker ones looked like cold leftover yesterday's BUTT as far as I was concerned. It all fit up under the car perfect and looked exactly like factory, even after I put a T-56 in it. These days your best bet is probably Dyno Don, unless you can score a good set of used SLPs which is getting less likely all the time.

For the motor I'd suggest a 96-2000 truck pullout 350. Pay what it takes to get the most cherry one you can. DO NOT mess with the short block; pay what it takes to get one with PERFECT bores, so you don't have to TOUCH it. Have a good multi-angle valve job done on the heads; put on LS6 springs, or their upgrade such as PAC 1218, with the Comp 787 "adapter" retainers; use a roller cam with high 2-teens or low 220s of intake duration, and up to .550" of lift, with those valve springs set up at 1.80" installed height; steel full-roller rockers such as from Comp or Crower (NOT "roller tip", NOT aluminum, NOT chinese knockoffs); the best Vortec 4-bbl intake you can find; and either the stock Q-jet and distributor, or a Holley 6210 and a Performance Distributors DUI. If you go the Holley route, very carefully remove the ENTIRE wiring harness for the computer, peel it back from the engine, remove it from where it comes through the pass side kick panel and routes through the fender well up into the motor, and put the whole thing, along with the ECM, sensors, etc. etc. in a box, UNLOLESTED UNDAMAGED and UNCUT, every piece intact and ready to re-install someday. A piece of sheet metal, some windshield sealer, and some zip screws will cover the harness pass-through hole. Consider a moderate converter upgrade, maybe 2500 - 2800 RPM or so, and a few simple transmission upgrades such as a Vette servo and a .500" boost valve.

 

You bought the car because it was in great condition for cheap. Now capitalize on that and have fun with the car. Make something you enjoy driving. Tinker with it, modify it, make some power, enjoy the hobby.

If you really want to lose money, then go with the plan where you modify a car that's not so nice. Condition is everything at resale.... stock or modified. And don't let the purists sell you on the myth that modifying a car lowers the value. That is pure bull pucky. Really nice built cars sell for a lot of money. The issue is that you only recoup a fraction of the money spent. But you've done this before so no surprise to you I'm sure.