Does a 89 305 TBI Camaro come stock with a flat pistons or not?

Thanks..

 

Yes although they have a slight dish to them.

 

Theyre dished pistons with reliefs. Not that thats necessarily a bad thing unless you need lots of compression.

 

If i were to use these pistons on my TPI would my car loose performance?

 

I didn't realize that they were considered dished. I always heard them refered to as flat tops with reliefs even though they had a slight dish. I stand corrected.

 

Heh, I always thought of them as basically flat tops but evidently any sort of slight dish is a dish.

I dont think theyd cause too much of a problem unless your running a cam with some serious overlap or something. What was the LO3's compression? Around 9.3:1 or so?

 

9.3:1 exactly dimented

 

Well, if you have a good LO3 shortblock then just bolt all the parts (heads, cam, etc.) from the LB9 and you should be good to go.

 

If I am not mistaken I think the 305 TBI and TPI's shared basically the same internals.

 

Identical internals last I heard. Heads/cam/induction were the only difference as far as I know.

 

Whats funny is I don't see how the LO-3 was rated at 9.3-1. I had a stock H.O. 305 in my monte and it ad true flat tops, No little ridge around the edge. With 58cc heads it was rated at 9.5-1. I know for a fact that those pistons are worth at least .5 to .75 points of compression.

 

My 92 GM manual says 9.1:1 for both the L03 and LB9, and 9.75:1 for the L98

 

I do belive they are -20cc and most flattops are -7cc or so. Gm is bad with castings 58cc is a roundabout figger most of the time more cc's than less