Hey guys im new here and am thinking about buying some sort of GM 3rd gen car for pretty cheap. Im looking at 2 right now a stock 87 iroc with 90k, an auto trans, and carburated 305. And a 86 firebird, auto, with the 305 TPI, exhaust, and some kind of suspension mods. I know the 350 is where its at but those are hard ot find in my price range i want to spend ~1500 on the car and then put ~1000 into it, and make it as fast as possible for that money, without too much risk of blowing anything up.

Basically what i want this car for is a more streetable car as i have a 91 jeep wrangler with an 11" lift and 38 inch tires which sucks on the road lol.

I want to know which one will be cheaper and more reliable to upgrade most likely with nitrous. I want to be able to give my buddy with a 94 trans am with the LT1 a run for his money. He has intake, mass air, and exhaust.

Also Ive read that 100-150 shot is probably what ill be looking for. Im not going ot be running it with nitrous alot but i want to be able to do it multiple times without blowing anything up. Would it be better to just run the lower 100 shot to be safe? Or are there somewhat cheap mods to make a higher shot safe? Sorry for my ignorance, ive only had a jeep, no sports cars.

Thanks in advance! ~Evan

 

Check RPO codes before you buy anything. If one of them has a 9 bolt 3.42 gear that would be the best bet, and DO NOT run a 150 shot of whatever. The TPI motors will not handle it. BTW regardless of what anyone says 150 shot will not put a 305 car into the low 14's.

 

Yeah i read about that, but i mean even the 10 bolt wasnt terrible, and im never going to be running more than 375 hp to the crank, and its an auto.

What about a 100 shot? you think either of these motors would handle that. Ive talked ot people who say they have run a 100 shot through these multiple times.

Also having never tuned a carb, ease of install and tuning if a heavy option as well. I know a properly tuned carb'd will always beat an injected, but im not looking to put alot of money and get every horse out of the motor just the ability to have ~300 hp.

Like i said before im no expert on any of these matters so i will gladly take suggestions. Thanks again

 

The carb'd car will be more tolerant to engine modifications than the EFI. However the starting baseline will be a bit lower, meaning it will require some modifications just to get to the level of the TPI. An '87 carb'd motor would be the LG4 with puny exhaust and low (probably 2.73) rear end. Assuming everything, sensors, carb, etc. are in perfect order you're looking at close to your budget for the exhaust mods required to make it perform close to the TPI.

You'll be able to go further, easier with the LG4 and everything will transfer to a 350 later on. Major mods to the TPI will require prom tuning and upgrading to a 5.7 will be a little more difficult.

 

For the LG4, if i took out the cat and mufflers, as ill get either of them tagged historic, and put like 3.73's or 4.11's (since thats pretty cheap, at least for the jeep it was like 150) How would that do for a budget upgrade?

And how much nitrous could one of these motors handle? Im going for most power for least money and from what i hear nitrous is the way to go. If i get another say 10-15,000 miles out of it id be happy.

 

The biggest exhaust restriction for the LG4 is the heads and y-pipe, pretty much everything from the heads back would have to be replaced. The power band for the stock cam (not to mention converter) wouldn't be compatible with any rear end over 3.23, IMO. Of course, the TPI's not going to like anything over 3.23 either.

 

If I was you I would go with the TPI motor, Plus I would say a fuel injected car is a little more reliable than a carb'd car.

And as for the nitrous thing I have put about 15 bottles through my car rangeing from 75-150 shot. But make sure the car has a good tune before you go putting a big shot of n20 on it. and dont forget to ungrade the fuel system if you plan on running any bigger that a 100 shot.

strage colder plugs
wot switch
I would go wet kit
AFPR

Just make sure the car is mech. sound.

 

First, If you put N2O on a 305( providing you have a sticky tire) 14's will not be a problem, if you have a decent gear and a good tune.

As for Carb/EFI, there are alot of EFI cars that will spank carb'd cars all day long. Such as modded LS1 cars. To give you an idea look at the Outlaw 10.5 series most are going to turbo'd efi cars b/c a.) they cost less, b.) most of the card'd cars run N2O and therefore go thru more motors in a season than efi turbo cars, hencethe fact for reason a. Now that is on the extreme side of it, but it still proves the point. Also, a well tuned efi car will have far better drivebility and fuel economy than a carb'd car hands down.
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........oh and btw a 305 can hande a 150 shot if properly built and tuned to handle it. hth

 

yeah youre right, a few guys on here are running 13's and even 12's on n2o 305 tpi's .

 

If it's a manual trans 87 it would have a cam that is significantly better then the 86, it's a roller motor with a 1 piece rear man seal and if you want to carb it later fine.

It's not like you'd wanna use the intake on the 86 anyways, possibly not even the carb so to convert to carb from TPI wouldn't be that much more if you wanted to later on. I'd check the RPO sheets for the gears too, IMHO they can make a huge difference in thow the car feels; supposedly the TPI cars only like ~3.42/3.73 gearing anyways since they produce tons of bottom end torque, just something to keep in mind not to overkill on the gears.

 

TPI (mainly for the ecm and intake you can sell it later if you really want a carb) and/or sell it to move to a HSR or lt1 on a 350-400

Do the free modes , AFPR (adjustable fuel pressure reg.)

NO cat, no smog, no a/c( if you can deal)

100 shot, with HIGH STALL like 3000-4000 (do this first, it will make everything funner), with the "unknown suspen. mods" and some good tires. SEEYAAAA LTwhat

 

The carb is going to be easier to afford when the power levels go up. The TPI is probably going to run a little faster stock for stock assuming same gearing and both in good running condition. BOTH need a good exhaust system on them and a proper tune-up. BOTH have basically the same heads and cam in them, the difference is computer controlled carb vs. computer controlled TPI. Neither is very desirable in stock configuration for mucho power. Both can be modified but the carb setup more easily and for less money (mostly becuase it's easier to ditch the computer controls on the carb motor and go "old school" with it).