I bought my '91 G20 used and I am very pleased with it. However, it leaves much to be sought after. Also it now has 110,000 miles on it which makes me lean towards not puting anything on it. What I'd like to know is if I'd be able to drop a newer version G20 engine (or the DET) into my present bay OR if it's possible to drop a different engine in the bay. And lastly, the general availability of any of these options. Any help with this would be greatly apprieciated. Thank You.