You fine people seem pretty smart. I have been scouring the internet for days now trying to figure this out. I have pulled a 3.6L LLT engine out of a 2010 Acadia that dropped an exhaust valve on cylinder # 4. I greatly dislike these 3.6L V6'*. Garbage. Anyway, I am having the hardest time finding a piston and ring set for the LLT engine. I know the difference between the LY7 and LLT are direct fuel injection and that the LLT piston has an extra scoop milled out of the top for the injector to spray onto I guess. Question is why can't I just slap a set of LY7 pistons in this LLT engine. It looks like all the LY7 rebuild kits come with flat top pistons with just the scoops milled out for the valves anyway???? Please help. As a side note, I am looking for a set of .030" or .040" oversize pistons and rings. The engine is currently at .020" oversize.

Awww shucks!

Wow, what kind of car was it on? How many miles on it. Just curious here.

Also curious: Why? The timing chain thing? All of the 3.6'* I've run into have worked well, and many have been stupid fun in rental cars.

Off the top of my head, the LY7 has 10.2:1 compression as opposed to 11.3:1 for the LLT . I can't imagine that'd work well. Piston shape has a lot to do with fuel and flame dispersion too.

The LLT is already overbored .020 over? I've never heard of overbore High Feature engines. Well, not in the US at least. Going .040 over is a lot, especially considering this is a cast iron liner in an aluminum block.

Those guys in Australia have been tweaking these things for years. Maybe search for Australian performance parts for this engine and see what you can find? I know I found a bunch, and they seem to think highly of several versions of this engine, mostly bashine on crummy and/or weak transmissions from what I can tell.