Difference between 10:1 and 10.4:1 1uz motors

[halcyon]

Anyone know what changes were made OTHER than the pistons and connecting rods to up the compression between the 10:1 and 10.4:1 motors. I have a 10.4:1 block and a set of 10:1 heads that i am looking to put together. I cannot find any information online about this particular setup. I also have access to a set of 10:1 pistons that I'd prefer to use if there is no fundamentals changes to the block that would prevent me from doing so. IF i can use the stronger 10:1 pistons, would I also need to source a crankshaft or would the high compression crankshaft work? I do not think the crankshaft matters, and I am thinking this would all work just fine, just I wanted to talk to some smarter folks and get the warm fuzzy feeling that I am just overthinking this here before i waste a gasket rebuild kit.

 

[4U2QUIK]

http://www.lextreme.com/tech.html

 

[halcyon]

I've read through every single article there, I see mention that the 10:1 rods are interchangable with the 3uz pistons. Is this what you wanted me to read? I am assuming what I specifically want to do is okay.

 

[krayn]

im not sure, but i think the compression difference comes from the piston. The 10.4 has a smaller dish in the piston. I had both a 10.4 and a 10.0 motor apart, and heads looked identical, but piston domes were a little different. I will have a look again and get back to you..