swissiroc

Does anybody running a 350 H.O. which was available from GM 82-87 ? Kit is not longer available, but ZZ4 from SDPC looks the same. I wonder how it runs and does the tranny handle it ? GM was announcing it with 308 HP using headers, but overhere headers are not allowed, so I think this engine will deliver about 280 HP without. I could find different answers about the tranny yet, some say it will work fine some say no, but I can imagine, cuz GM offerded this package, it should handle the power, especially without headers.

Thanks


85 IROC-Z28 LG4 double airsnorkel, Edelb.RPM mfld, Flowmastercatback, no cat, tinted window, t-top, sbfc, Centerline wheels

Z28SORR

You will always get mixed answers about this, because it depends so much on how you drive.
I installed a 383ci. in my 84 Z28, 5 speed. It produced 411ft/lb of torque. I drove it for years with the stock trans. and rear, with no problems. Others have broken within days of up grading.

Sitting Bull

ZZ4s are advertised by GM as having 350 hp, not 308.

The 350 HOs were advertised as having 330 hp, if I recall correctly.

Ray86IROC

What he's talking about is the 82-87 or whatever it was, emissions legal ZZ4 conversion kit. It was a ZZ4 and all the goodies to convert a carbed thirdgen over to the carbed ZZ4 and remain 50 state (I think) emissions legal. It was rated at 308hp, however that was not with headers, that was with the TPI exhaust manifolds/y-pipe/dual cat setup from the 350 TPI/305 TPI G92 thirdgens (setup was included in the kit). It also came with the dual snorkle "HO" intake setup, along with a cat-back of somekind I believe and some boxed lower control arms.

I would think it would be pretty easy to duplicate the kit, as you should be able to buy the exhaust setup used online somewhere, and as stated the engine used in the kit was a standard ZZ4. I don't have the spec sheet handy anymore to list what all else was in the kit, but I think I've listed the main parts you'd need. Search ebay and the classifieds here and on www.thirdgen.org and you should be able to find the dual cat exhaust setup and the HO aircleaner setup if you decide to duplicate the kit... From your sig it sounds like perhaps you have the HO air cleaner setup already. And from the sounds of the no-cat tidbit emissions aren't as strict in some areas over there. Seems like you should be able to drop the ZZ4 in without much hassle using a good dual cat exhaust setup instead of headers and get right at the same 308hp the kit had... You wouldn't want to try to get by on the LG4 exhaust setup though, the dual cat TPI setup was considerably better.

Oh yeah I missed if you had the manual tranny or not, but the kit was listed only for auto equiped cars I think. Mainly for emissions reasons but also because the torque would be over the max factory torque rating for the T5 tranny, but as someone stated above lots of people have used the T5 behind hotter engines than this with success, it's all in how you drive it... The standard 700r4 if it's in good condition should have no trouble, if your's is worn out a rebuild may be in order. You should be able to get by with either tranny IMO, the T5 will always be in danger of grenading if you beat on it too hard or blow a shift in the middle of a race though...