Originally Posted by 7mm_Loco
Originally Posted by Stormin_Norman
Originally Posted by RiverRider
Originally Posted by 7mm_Loco
The Oldsmobile 403 has a fantastic (over square) Bore & stroke ratio for performance... 4.351 bore, 3.385 stroke... but the blocks and cranks were weaker than schit (typical GM stunt)... i've got one in my 79 Trans am, i upgraded to a nodular "N" crank, main studs and straps and a big oil pump... ported W-31 heads, Hi-rise intake, headers & hot cam... makes 425 ft lbs @ the rear wheels... mid range is fantastic, wants to rev like a 302, Wails like a Banshee... but every time the tach gets above 5500 RPM i get a qweezy feeling in my stomach... it's holding up so far... lol

IIRC, if the hood scoop decal on a Trans Am said "6.6 L," it had the Olds engine and if the decal on the scoop said "6.6 T/A," it had a Pontiac 400 in it. Am I right?? Just want to stress my memory a bit.

I had a 76 with the Pontiac 400 in it. I drove the everlovin' shit outa that car.

I think the 78/79 were olds 403 with an auto and the Pontiac 400 with the manual trans.
you are partly right... the 403/auto combo was a "California Only" thing until 79 when all automatic equipped 6.6's were 403's... in 77 i think? the 185 HP version of the 400 Poncho were automatic only, while W72 200 HP version were 4 speed only... i know for fact in 78 the 185 HP's were auto only, while the now 220 HP W72 was available with auto or 4 speed... in 79 the W72 400's were only available as 4 speeds, the 185 HP version 400 was gone, (replaced by the 403 Olds)... hope that clears this GM ClusterPhuqk Up, lol

Brings back memories, had a 78 Formula W72, 4 speed. With headers, true duals, 1.65 rockers, and a tune it was pretty quick for a low compression 400. Clutch was really heavy, but fun car.