Mr. Wizard

most made were THE GXP followed by the base G8 which used a 5.3 liter 303hp LS1 V8

the authenticity of my car has as long as i have owned it been questioned by those who believe that no 45's were available factory installed after the 1976 model year productions, but in fact the 455 Pontiac was available factory installed in any number of Pontiac Models INCLUDING the Trans Am from July 15, 1969-June 30, 1979...folk mistake the announcement in May 1976 that no more 455's would be available factory installed after the end of the then current production cycle to mean after the end of the 1976 model year production...a model year production begins July 15 of the year number proceeding the model year number and ends on June 30, of the model year number, while a production cycle at GM since July 15, 1949 has begun on July 15, of the 9th Year of a decade and ended June 30, of the 9th year of the next decade...GM as do all domestic auto producer produce on what is known as a 10 year planned obsolescence cycle, where after 10 years all productions within the previous 10 years become OBSOLETE and replacement part production rights are sold to the AFTER MARKET while the stock of the manufacturer of the parts is DEPLETED and no further production of these parts are done by the manufacturer...I am the 2cn owner of my car purchased from the estate of its original owner in May 2000 2 years after His untimely death, it took from May 2000 till June of 2001 for the sale to clear the Michigan Estate regulations concerning sale of property from the Estate of the deceased so as to insure that all applicable taxes on the sale are remitted, as well, the Car is a Registered Michigan Historical Vehicle and came with Michigan Historical Vehicle plates which must transfer with the vehicle into the name of the next owner.....Pontiac Nomenclature for my Car is 1977 455 H.O. 4spd WS6 Pontiac Firebird Hurst Trans Am which is what 1/15/1974 replaced the 455 S.D. Pontiac Firebird Trans Am Trim Code...the 455 H.O. was the top engine option available and equipped with this engine deleted the availability of some items among the option list on the car; AC, Cruise Control, Automatic Trans, T-Tops and Power brakes; altho the 4 wheel disc brake option w/o power assist that my car has was available and actually recommended, my car also came equipped with the functional cold air shaker system available w/ the 455 S.D. tho it is cable actuated while for the 455 S.D. it was Vacuum op'd...this , as with the other items deleted from availability with the 455 H.O. because the engine had a mechanical compression ratio of 7.9-1 which resulted in a vac signal considered to weak for options that were vac actuated in whole or in part such as power brakes, cruise control, AC and automatic trans, the T-Top availability was deleted in the Trans Am because the Trans Am version of the engine was rated at 290hp/435lbft and 4 spd only available and it was considered that a T-Top Body construction was too weak for that amount of tq and hp application with a manual trans....