In respect to this question obviously not, or I wouldn't need to ask the question but I thought someone might have some, more constructive answers, ie the reply they are two completely different engines thanks for that one and others. Are the two engines in fact completely different I find this difficult to believe as costs to do that would I think have been prohibitive, yes there are significant differences and vast improvements but was the basic block changed or altered and if altered can this also be changed on the 3Ltr block .. As stated above the 3.5 2gr block and 3.0 1mz are not going to be compatible for a parts interchange. There is at least a decade between design of both engines. If you want more capacity you will need to source a 3mz which is a 3.3litre engine. In Australia it came in the 1st gen Kluger fitted with drive by wire throttle and vvti on the intake cams. It should also be possible to bore the 1mz to 3.3litres as these blocks are nearly identical. One of the main differences was the use of better conrods in the 3mz compared to the 1mz. Wikipedia page on the MZ series of engines.