If the enginge is stock it came from the factory with 165 hourse power.
Advertised horsepower is....160Hp @ 4400 RPMs.
150 ponys
The original equipment 305 cubic inch (5.0Liter) was factory rated at 150 horsepower
ASSUMING ITS A 305 ITS ABOUT 475 LBS WITH ACCESORIES
From 1978-1987
The 5.0 305 C.I. V8 line came with 180 horsepower.
155 HP @ 4400 RPMs
The Monte Carlo SS didn't have a 350 in 1987, but the 305 had 180 hp
Base 305 4bbl (170 hp), optional 305 TPI (215 hp) or 350 TPI (225 hp)
The 305 "HO" was actually dropped after 1986. In '87, the base 305 TBI was rated at 170 hp, the 305 TPI was rated at 215 hp.
"A stock 1987 Camaro Z28 305 V8 engine has at least 280 horsepower" Sorry, but the '87 305 only puts out 165 to 215 hp depending on the performance package. The 350 of that year only increased this by 10 hp to 225. Source: http://www.thirdgen.org/1987-pontiac-firebird
Either a 262 cid V6 or a 305 cid V8.