tranny

I got a 98 gtp is it possible to drop a standard tranny in it? if so has anybody done it??

Why? The standard transmission is not designed to handle the extra horsepower.

The GTP uses the 4T65E-HD transmission due to the horsepower produced by the supercharged engine. You can put one from a na 3.8 in the GTP and you shouldn't have too many issues, in fact the gear ratio is different and can give you a performance advantage. If you want a high performance transmission check out the one from ZZP.

yeah i always thought that a standard transmission gave you a performance advantage over a manual

I would just stay with the auto putting a manual in would be a pain. mounts, axles, cables, all the interior mods plus the plumbing for the hydraulic clutch. You could stay with the 4T65E HD or you could use the plain 4T65E. The only thing that is HD about it is the Diff. and the related components in that general area and possibly the final drive ratio. The clutch packs are all the same and so is the general stack up of the unit. the durability is somewhat improved. Also you could have a different drive/driven sprocket ratio if you don’t find the correct match if you don’t have it rebuilt.