Is there really much of a difference in these TPI motors? (Other than size)
There doesnt seem like too much of a difference in power. Only that the 305 auto doesnt come with anything but 2.73 gears (correct?). Those gears seem kind of weak. Guess Im used to 3.73 and 4.10 trucks.

 

Huge difference in potential and how much $$ it takes to get it over 300hp. I would either do a 305 5spd or a 350.

 

350 has larger injectors
350 has 5500 redline
350 has rear disc some 305 have this aswell
350 has more power
go with a 350 you will kick yourself if you dont

 

Just as Shaun 90 IROC said: go with a 305TPI 5spd (preferably G92 if you can find/afford one) or a 350TPI. If you planning on modding the car a lot, go with the 350TPI or you will go through T5s like a hot knife through butter. However, if you're rich , it would be much easier to swap in say a Tremec or T56 in the 5spd car, but you're still stuck with the 305, and if you're rich, you can afford the automatic to manual swap anyway so...

350s are great motors and the mods for them are almost endless. They may cost more when it comes time to purchasing one, but they are much easier to make fast. The 350TPIs initially came out in 1987 and continued throughout the life of the Camaro. Here are the different stock specs during the 3rd Generation:

1987 350TPI: 225hp@4400rpm 330ftlbs@2800
1988 350TPI: 230hp@4400rpm 330ftlbs@3200
1989 350TPI: 230/240*hp@4400rpm 330/345*ftlbs@3200
1990 350TPI: 230/245*hp@4400rpm 330/345*ftlbs@3200
1991 350TPI: 245hp@4400rpm 345ftlbs@3200
1992 350TPI: 245hp@4400rpm 345ftlbs@3200

*when dual cat option was added

305s are decent motors, when linked to a 5 speed with the G92 option (3.45 pre-1990 and 3.42 1990-92 rear end gears) they are excellent cars! Any 5 speed 305TPI Camaro got the 350 cam, which is the reason for the differences in power rating below. However, the good 'ole Borg-Warner T5 can only stand so much hp/torque (reason they were never put behind the 350s), so too many mods will cause you problems. 305s can be made just as fast as a 350, but it will take more mods and more $$, but you can't beat saying "yeah it's only a 305." I have an article from the late 80s with a 10 second 305 in street trim (car was S/C and built up quite a bit).

Instead of writing out all of the specs, I found the page with all the different ratings from the Third Generation Camaro.

http://www.thirdgen.org/newdesign/tech/techdb.shtml

I could go on and on about this topic because I love comparing and contrasting the two, but I'm getting sleepy.

 

Sweeeet thanks so much. What I would really like is a 350 TPI with T56 ( I can mod later on ) but a manual in this car seems kind of odd for me. Last time I drove a 5 speed z28 it felt a little difficult to shift (just by the way the interior is designed). Apparently not a car for long trips in the city.

And the reason why I wanted a Z is not only because I love the body style but also I currently have a 95 standard cab/ short bed Silverado with the TBI 350 (same design as TBI in the RS? - just a little bigger of course) and I get about 18 on the highway and 16 in city. I take some trips to see family (currently in college) and a little power combined with gas mileage would be nice. The TBI in the truck is an absolute dog... but of course being the lightweight version of the fullsizes I could do burnouts all day long. Its just that after 2000rpm it just dies out. (One reason why I wanted to stay away from the RS).

 

i love saying "it's only a 305"

 

Baddest305...your car is nasty. I have looked at it quite a few times! That's the way to do things with a 305! haha

Pro...TBI motors in RSs...ehhh alright if you don't want to make a lot of power. Of course you could probably do burnouts all day, it's a Chevy motor! Z28s are very nice cars, especially in the 3rd Generation with the nice-looking Z28 wing and the 350TPI option. You could get a 305TPI in an RS, but not a 350TPI, unless you get a B4C (police package car), where the 350TPI was an option. B4C cars with the 350TPI were essentially Z28s in RS trim. Factory sleeper . They are rare, so when you find one (I've only seen them on eBay and very occasionally in car mags around here), it probably won't be cheap. Sometimes they are well-maintained and are in good condition, while others are the opposite and are in need of work. Most of the time they have higher mileage, after all, they are cop cars.

Unless you get tips from Baddest305, try to get the 350TPI.

 

Agreed with ZRated - get yourself into an L98 car (350 TPI).

I've got an '89 GTA with the 350 Tuned Port engine and its a great daily driver. These things have so much bottom and mid range torque it feels like a mild big block under the hood. Just take a gander at that 345 ft/lb torque rating in ZRated's power by year listing. The 350 TPI with the dual cat option (N10) has the same torque output as even the mighty LS1.

 

Dollar for dollar, go w/a 350. Do a search, there was a thread a little while ago that got into this.

Ya, they can be made fast, but will cost more to get the same ET as a milder 350.

 

I remember when I was shopping for a daily driver and test drove an 89 Formula 350 twin cat. That low end torque combined with the 3.06 gear in the TH700 made for an eye opening experience. And this is from a guy who has owned big block Nova's and 442's.

I bought the car.

Definitely 350 if you can find one in good shape.

 

IS there much room underneat for a 2 cat conversion?
I dont understand why GM wouldnt put 2 cats on all the models of Camaro/firebird if it would up the horsepower ratings (and decrease emissions).

 

Yep, the room is there. My car has the dual cat option, and it looks to me like its packaged nicely under there. The dual cat option was for those who want the max. power they can get from the factory, and were willing to pay extra for it.

 

I was always told (at least in the truck arena) that the best package to have for small block chevrolet motors was a 3 inch single cat exhaust system. Something about losing low end torque when going with duals?