mikeceli

iTrader: (2)

Hi folks. I recently bought a 1989 IROC-Z convertible w/ the CA. 305/5.0 LB9 and w/ auto trans.

Just considering a 350 upgrade, for street use. It must be compatible w/ smog, EGR, etc. I want to reuse manifolds, AC, etc.

I desire a new or reman long block. What say youse? Thanks.

thtanner

iTrader: (1)

L98 w/ TPI?

mikeceli

iTrader: (2)

I forgot to specify, I definitely want to stay w/ roller lifters and would prefer a one-piece rear main seal.

mikeceli

iTrader: (2)

Gee, 56 views and one response? Is my question too difficult?

aliceempire

iTrader: (14)

Not really too difficult but a day hasn't even passed and you leave that. Not exactly the best way to get further replies but I'll give my thoughts on the question.


To reuse everything your car has and stay emissions legal you don't really have any NEW options. The common "go to" for tpi users is to switch the tpi base and use the vortec long block. But those heads have no heat crossover so to retain the egr you need to modify your headers/exhaust manifolds to send exhaust gases to the intake manifold. Which kinda rules it out based on your needs.


Leaving the only easy option of a reman from NAPA or the like. I think most vendors use ATK remans....I've heard both good and bad reviews. Just make sure you get 083 heads on it.


Otherwise you might want to do what many of us have done and build your own 350 to the specs you want.

mikeceli

iTrader: (2)

Thank you both for your responses!

I got frustrated because knowing I was dealing, for the first time, w/ the common, plentiful, Chevrolet Gen I small block, there would be LOT's of choices. (I've been seeing new GM 350 long blocks for $1499 type bargains, for years)

I have a rebuildable 1996 LT1 LONG BLOCK, that I thought would be impracticable solution. Am I wrong?

I would consider a JASPER reman long block (ATK is out, based on my prior experience).

"Aliceempire" what do you mean by "switch the TPI base"?

Could yous please tell me more about the L98 w/ TPI?

I just bought the IROC-Z and have not evaluated it's 305 engine yet, it just seems like a "today's horsepower 350 " would be fun!


Thank you!

aliceempire

iTrader: (14)

Problem is, within your criteria the options go way down. I ran into the same problem years ago but I was building one and the heads were my first issue.

A LT1 is a way different animal. Many things interchange but many more are not. Considering you're in CA, even if you put the LT1 in there with all the emissions in working, I still don't know if CA would pass it. I've never dealt with it there so I can't say for sure.

Jasper is a good choice, I deal with them at my work. I should have thought of it before. But remember they will want a similar core 350 back, so you'll probably have to eat the core chaarge if you don't.

A TPI intake consists of 5 parts. The base (part that bolts on the engine.) 2 sets of runners(the tube lookin things) The plenum (the long hollow part between the tops of the runners) and the throttle body (the part with the butterfly valves that the gas pedal opens.) Vortec heads do not bolt to the intake manifold the same way older heads do, therefor you need to change the manifold base when using vortec heads.

L98's are all tpi engines. But take the intake off and it's still a L98, so while I can't speak for thtanner, you would want a l98 long block.

Probably a good idea to start major searching and reading. Especially on 305-350 swaps. There's a really good sticky on the boards.

mikeceli

iTrader: (2)

Thanks again!

mikeceli

iTrader: (2)

How about this? It lists "one and two piece rear main seal" (I guess you can specify). Dosent mention roller lifters.

http://www.ebay.com/itm/CHEVY-350-EN...HGlFiCiFkanJcw

aliceempire

iTrader: (14)

The pictured one they show is not a roller cam. You'd see the sipder and dog bones in the valley. The heads on that are also terrible. "Pistons - Speed Pro Hypereutectic 9.5:1 comp ratio" and "Heads - GM 76CC Cast iron w/ new valve guides & seats" equates to probably under 9.0 compression....so not good. Plus I don't know if anyone on TGO has used "Connecting rods - GM 3.750".......GM rods are 5.7 inch. Gonna guess a typo for stroke length but I think I'd steer clear personally.

mikeceli

iTrader: (2)

I just received my GM Factory Shop manual (FSM) for my 89 IROC. I see the 305 and 350 use the same emission devices, including EGR.

Since, the LACK of EGR heads is what keeps me from using an L31. What heads did they use on the 1989 350 that accommodated EGR? What equivalent(or better) heads exist today?

I am thinking maybe I could use a 1 piece rear main seal/roller cam short block, w/ some good ERG heads? Reusing manifolds and accessories (and switching to a different TPI lower section, as was previously mentioned).

THANKS.+

sofakingdom

iTrader: (1)

Simplest, eeeeeeziest, lowest risk, most certain thing you can do, is just find a whole L98 long block.

That being, the 350 that came in a Camaro or Firebird with a 350.

That eliminates all concerns re. EGR since it was included; all concerns about switching bases since it used the same base you already have; all concerns about 1-pc RMS and roller since it has those things; and so forth.

This would be so close to the same thing you are taking out, that it almost doesn't qualify as a swap. All you'd need to make it run PERFECT, would be a set of larger (350 sized; 22 lb/hr) injectors, a 350 knock sensor, a 350 PROM, and a 350 ESC module.

L98 ones. Casting # 083.

aliceempire

iTrader: (14)

Sofa already covered a what I would say in a proper reply. I will add for clarification that the tpi base won't need to be changed unless you would use vortec/L31 heads.