Well, I just can’t seem to help myself sometimes when a post like this one come along. I tend to keep just about everything I ever read about cars (gotta love computers with big hard drives) and it just so happens, I’ve always liked Z-28 and Trans Am platforms. Of course, “Smokey and the Bandit” is an all-time favorite and who can forget Pontiac's screaming chicken in that movie set to Jerry Reed’s Eastbound and Down?

In 1979, things really changed for the Trans Am. The last of the 400’s were built in the fall of 1978 and they were never to be resurrected. They were rated somewhat conservatively at 220 horsepower @ 4000 and 220 lb/ft of torque at 2800 and darn few of them found their way into the Firebirds. All 8,326 of the 400 engines (RPO W72, VIN Code “Z”) were mated to Super T-10 four speeds at the factory. Hottest TA? – a real 400 with 3.23 rear end (RPO 2PX). During road testing Car & Driver magazine sent the tach past the 5000-rpm redline to reach 132 mph at 5400 rpm. This was one of the last cars whose top speed was gearing limited rather than drag limited.

Also for 1979, one could opt for the WS6 package that was upgraded to include disc brakes at all corners. The rear disc brakes measured 11.1" in diameter and were had the same internal vents as those in the front to keep them cool –pretty cool, eh? Problem was that GM didn’t make enough of the disc brake axles and the WS6 package was soon depleted. A “true” WS6 today is rarer than hen’s teeth.

The most popular engine/transmission package was the 403 with a TH350 automatic - 94,773 units. The 403 (RPO L80, VIN Code “K”) was really an Oldsmobile small block engine and was, well – disappointing. It was rated at 185 horsepower @ 4800 and 320 lb/ft of torque at @ 2200. It’s easily identified by the oil fill filler at the front of the engine (kinda like an early SBC). Most 403's were 2.41, 2.56, or 2.73 rear-end ratios which hampered their launch.

A four barrel 301 V8 was available for the ‘79 Trans Am. Mated with either a 4-speed manual or three speed automatic, the engine (RPO L37, VIN Code "W"). It was rated at 150 horsepower @ 4000 rpm and 240 lb/ft of torque at 2400 rpm, and it was a true dog. The 301 was originally designed for compacts (Sunbirds…) and mid-size cars. It had a lightweight crankshaft with only two counter weights so the reciprocating mass was again “more fuel efficient” but no bananas when you smashed the go pedal. The cylinder heads were new for this application and had Siamese intake ports and tinny valves - 1.72" intake and a 1.50" exhaust.

If your TA is truly a 400, it could have only been a T-10. If it was a TH350, it was either a 301 or more likely, a 403. There was never a TH400 in a 1979 Trans Am from the factory. The last T/A's with TH400's would have been the '74 455SD

Regards,
Glenn