I have an Lt1 and 6 speed out of a 94 that im going to be building and thorwing in my car soon enough. I wanna know a little bit more about the 94 engines...diffrences in those vs. the 95-97's?? pro's and con's...or are they just all the same, and info would be appreciated!

 

Main difference will be non-vented Opti setup on the 94 versus a vented Opti on the 95-97...do a search on Opti or vented and you'll find tons of discussions.

 

I've also heard that the 94s all had hardened pushrods and only some 95's did...Not really sure what all differences there are but the opti is the main one...When did they go to obdII from obdI?

William

 

1.) A 94 will be OBD-I and single cat.

2.) 95's will be OBD-I but with an OBD-II connector, single cat on M6 cars and non-California A4's, all California A4's will be dual cat (but with NO O2 sensors AFTER the cats).

3.) 96+ will be OBD-II with dual cats and O2 sensors before and after each cat.

 

94's have hardened pushrods. 94's are also very accepting to deletion of egr and AIR without any computer tuning. u can pretty much take off all smog without much or any problems. most of the time the stock computer doesn't even mind such things. it is a nonvented opti, but you can argue all you want on which is better and if it is worth converting to. thats about all i can think of that is different from the 94's and other years. I'm sure the pros will have more to add

 

Thanks for the info guys...keep it coming! Blackztpi...I see you got a 94...what are the diffrences between the two opti's? I was thinking just getting a hole Drilled in the back of the intake and just running a distributor and using just my TPI harness and computer..but then again I'd like to use the harness that came with it so I'm leaning more towards just going the opti route.
Now the 94 came with hardened pushrods...are those better? the motor does have 110k on it so I do plan on getting it rebuilt..I'm either going the cc306 cam route or getting the hot cam kit and then getting a set of GM stock replacment lifters just to freshen it up a bit. Pistons im not sure yet, I hear the come factory with Hypereautics?? I'll assume the factory compression is around 9:1 I'd like to bump that up a bit mabye 9.5 or mabye 10:1 leave a little room to throw a little shot of the squeeze after that.

Oh yeah and I do not plan on running EGR or AIR set up/ I currently have none on my L98 right now either

 

i do believe that factory compression is 10.5.

 

According to the calculations I did using the formula, it is 10.4:1. W changing to Impala head gaskets, mines at 11:1 . To confirm about the pushrods, yes '94's have hardened push rods. I also agree about the EGR removal, as within the last week two of my friends removed theirs ('94's also),and up until today when I tuned it out, they weren't throwing a code.

 

Thats cool, I'm starting to see that these motors have some potential and I can't wait to start working on it! Anywehre I can get actual motor specs stock from the factory on some web site somewhere?

Should be interesting to see there's not too many third gens around this area that are nice, let alone with any unique mods and I think mine will be only one that I know of that has an Lt1 or a t56 swap for that matter. My buddy has a 6 speed in his 83 but his car is just out of this world..behind a 383 stroker twin turbo motor but other then that, i havent seen any.

 

this may help you out a little.....i have been following this story since they first started. I is a 3rd Gen they are putting an lt-1 into.

http://gmhightechperformance.com/tech/0409htp_snow/