mystery Pontiac motor

[Guest marlin65]

My body shop manager was talking to me yesterday about a Pontiac motor sold thru the parts department for 67-68 Firebirds&Trans-Am's.He had seen mention of it in a era hot rod magazine and thinks he knows of a car with this motor in it.He thought it was about 428 cu.in.,but again going from memory from years ago.I told him i would ask on this forum since i'm not a Pontiac person.Anyone know anything about this motor and how to identify it? Thanks.

[WQ59B]

Sounds like 'Service Replacement' motors- if so they are coded in the numbers stamped into the block.

My brother had one in a '68 Firebird- it was a 400 and if I recall, the number was preceded by 'SR'.

The nature of these would mean, IMO, that all displacements were available.

Whether a 428 made it into a Firebird would've been up to the owner / dealership.

[PONTIAC1953]

hi wq59b, i think you have misunderstood the question, the reference was to a special high performance engine option that wasn't available thru the showroom, but knowing how to order one thru the parts department. there wasn't any firebird in 67 to 69 built or ordered with an engine larger than a 400. there was two special order racing engine, 1969 you could order a 303 pontiac racing engine, and in 1970 you could order a 366 pontiac racing engine. 1971 was when firebird or trans am could be bought with a 455 pontiac engine. charles coker, 1953 pontiac tech advisor.

[Guest]

There were dealers that would install the 428 in Firebird, and GTO from 67-69. Anybody could also order a 428 crate from a dealers parts department. BTW the 428 Pontiac is really a 427. There is a reason it's really a 427 besides the math.

D.

[NTX5467]

As I recall, the original "Trans-Am" racing series had a 5 Litre displacement limit on the engines in the race cars. Chevy had an easy combination with their 302, Pontiac did their 303, and Chrysler had a similar-sized engine based on their LA 318/340 engine family. In that orientation, I could see Pontiac offering a 303 crate engine for those who raced Firebirds in the Trans-Am race series. The ultimate owners/crews might well have fully-disassembled these crate engines to verify sizes and clearances, but as many later Chevy crate engines, that was the best/most economical way to purchase them. Production '69 TransAms came with a 400RA V-8, but race TransAms had to have the 303 V-8.

Just some suspicions . . .

NTX5467

[Guest]

The 303 did not make in time for the 69 T/A racing season as a Pontiac, however the Canadian Firebirds with the 302 Chevy engine did. For the 1970 season one car only ( Jerry Titus T/A ) ran the Pontiac 303 not as a tunnel port, but with R-A 4 round port heads. Somewhere in the middle of the 1970 season the T/A rules changed and so the 303 project was dead. There were three engines that came about from the tunnel port development era. The 303 for T/A, the 366 with RA-4 heads for NASCAR's new rules and a 428 (427) NHRA Pontiac also experimented with a 400" RA-5 . The three engines use this basic head ( tunnel port ) which Pontiac called RA-5 short for Ram Air five. None of the engines went into factory production cars.