In 1985 there were 44,028 Trans Ams produced. The "power bulge" hood was removed and replaced with a new flat hood with non-functional twin louvered nostrils. The Trans Am also received a restyled nose with integrated foglights, ground effects were now standard, and new low-density tail lights have a grid pattern.
A new Tune Port Injection fuel-injected engine was an added option only for the Trans Ams. It was a 305 cubic inch 5.0L engine with 9.5:1 compression that produced 215 horsepower @ 4400 rpm & 275 ft. lbs. torque @ 3200 rpm. This was backed by a THM 700-R4 four-speed automatic with overdrive transmission.
The gear ratios for the THM 700-R4 are as follows:
..........1..........2..........3..........4
-------3.06-----1.63-----1.00-----0.70
The new engines had a decent camshaft with the following specifications:
........Lift..........................Duration...............Lobe Seperation
Intake..Exhaust..........Intake..Exhaust..........Intake..Exhaust
-.403-----.415-------------202-----206-------------115------114
This was big compared to the smaller camshafts that came in the 305 TPI automatic equipped cars of the later years (86-92). They had camshaft specifications as follows:
........Lift...........................Duration...............Lobe Seperation
Intake..Exhaust..........Intake..Exhaust..........Intake..Exhaust
-.350-----.385------------178------194-------------106------112
The 86-92 350 TPI automatic and 305 TPI five-speed equipped cars came with camshafts similiar to that of the 1985 305 TPI.
These cars came with a 9-bolt rear with a standard 3.27 gear ratio and an optional 3.42 gear ratio. The torque of the TPI setup, the low first gear of the 700-R4 transmission, the decent camshaft, and the rear gears combined nicely for a good street combo.