On the GM parts direct web site http://www.gmpartsdirect.com/ I see that they list a ZZ4 crate engine for sale. Since my engine is really getting up there in miles, (320,000) I have to start planing for the day when I'll have to yank it.
My question is, if I bought this crate engine, what mods would I have to make to make sure everything harmonizes up with the existing ECM and other things like A/C ect..ect...(Oh, its an 89 305 TPI.)
Thanks in advance...
Viking

 

yes you can put a ZZ4 in you iroc.... i have an 89GTA that i am about to do just that to... if all goes as planned... i am going to put the zz4 in with a lt1 intake... slp headers... slp catback exhaust... SVO 24# injectors... and a converter with a 2400 stall.... and a cutsom burned chip... i have been told that that is about what i will need to make it run pretty much as good as it will get..... and i still will have my a/c and all... oh and mine is a 89 GTA which is basically the same as what you got!!

 

Hey Chris, I've got an 89 GTA as well. What about using the TPI system (MAF) on a ZZ4. possible?
Or, should I just rebuild the 305 and use World Products 58cc heads w/the TPI.
I'm thinking the ZZ4 would make more power, but it'll be double the cash right?

 

steve,
yeah you can use the tpi on the zz4... but from what i hear it will totally choke out HP from the engine... the tpi is great on low end torque, but around 4000-4500 rpms it will choke out the zz4s possible high end rpms... the zz4 would definatly make more power than rebuilding the 305... from all the people i have talked to... most have said that if i can afford it... get away from the 305.... but if you want to rebuilt it you can... just make sure it is done right... how many miles is on your car?

 

I've got 110,000 miles on the car now. Runs strong - consumes a touch of oil but not much at all.

 

yeah... mine has 95,000 on it... and i had really considered just rebuilding the 305 to save money... then i talked to some buddies of mine who told me just to go buy a crate engine to prevent having problems with the 305 block having 100,000 miles on it... if i had rebuilt the 305 and it busted.... i had just wasted a ton of money...

 

Thanks for the help man.
I'd like to go with a crate motor as well (can't beet new $hit) and I definitely want to do it right the FIRST time. I had SDPC quote me that p/n 12513151 is the correct replacement motor for my car from GM. I looked it up on the net and it said Caprice??? 91-92. Strange, anyway.
What motor can I get from GM that would accept my TPI? Can I get a new LB9? Contrary to most, I'm quite happy with the performance of the car now (get all my kicks from my yamaha r1)...and I think with a new lb9 coupled to World Product heads and a nice cam...it'd be good to go.
But while I'm at it, I might as well go with a new L98 correct? All I have to do is maybe change the injectors ( I heard 19ibs are good enough though for 350hp) and an l98 computer?

 

yeah man... if you want to you can get a new LB9 engine for the car... and it would run pretty good with the World Products heads and a cam on it... but if i was you and were thinking of putting new motor in, and were looking at either the LB9 or the L98 i would go with a new L98... and yeah i think the 19# injectors should do with that motor.... and the L98 computer... and you could also add a mild cam with that for a little better performance... but i know the feeling with the money issue.... if you like the performance of the LB9 you have now you would be happy with the L98... it would give you a little more to work with power wise... and not run you too much in the money catagory..,