Welcome to the site! Here's some info on the "top-swap".
1) - Top Swapped 3800 V6 (GT Only) – Don’t cry you non-supercharged guys, there is still hope on how to lay a smack down on a factory supercharged car and that lies within your block. Yup, Compression Ratio. Higher Compression means a few things for you who go the top swap route. One, you will make more power on the same sized pulley as the factory L67 powered car. Two, High Comp. loves boost. It is easier to blow motors with too much boost and high compression but when tuned correctly is a very lethal combination that will beat most cammed and intercooled L67 cars. Here is the thread I would more than advise reading on the Top Swap (There is also a lot of great info in this thread too): http://www.grandprixforums.net/f17/t...lots-7763.html (Top Swap Info and Faqs, Also lots of 3800 Info) . This isn’t the easiest thing to do, nor is the hardest, you do have to tear the block down to the heads. Cost: $700+The GS has 2.93 gears, the GT has 3.29 gears. The GS has a HD transmission that is marginally stonger along with heavy duty halfshafts.Also I am under the impression that the tranny's are different as well. Is it just the gearing and ratios that are different or is the GS tranny built better to hold the power of the supercharged motor?
