I have a 1991 trans am, its an auto, T-roofs, 305 tpi, To my understanding there is 2 typs of 305s out there, one has 205 horse power, the othere one has 220, what code, orsomthing tells me which one I have? any help would be greatly appreciated.
john

All of the 230 hp TPI 305s came with 5-speeds and 3.42 gears. But some 205 hp 305s came with 5-speeds as well. They were both called LB9. If you have 3.42 gears you have the 230 hp version. The 8th digit in the VIN would be an "F" for the LB9. Look under the center console lid and look for a RPO code GU6 for the 3.42 gears.