If a top end swap was done a long time ago, perhaps it was done in an attempt to lower compression when gasoline octane (and lead) started to drop. I could see an original owner ask a dealer to ‘update’ it in the early ‘70s, or later in its life someone getting a deal on the smog parts and thinking it a good idea. Just a theory, I do agree though that even a smogger should have more punch. What torque converter is in it? A too tight converter can hurt, too. Patrick
The PP code 350 on my '68 GS felt a little sluggish, its still not to where I think it should be. But I put a looser converter in it and put a pertronix ignition and bumped up the timing. It made a noticeable difference. I think the 2.xx rear gears are whats hurting it now. It'll spin the one tire all the way through first but that's about it. Also, the downpipes off the exhaust manifolds look like they're smaller than 2" - so I think they are choking off some of the exhaust scavenging. And I can't find 2.5" down pipe pieces for SBB for A bodies anywhere. I think this would make a noticeable difference.
I am sure you have your ignition timing optimized. The truth is that both the GS350 and GS455 were pigs in 1972 IF they were timed according to specs. I have posted this several times but it bears repeating. Have a look at the Ignition System specs for 1972, Do the math. Total wide open throttle timing with the GS350 would be 16-20*. For the GS455, it would be 18-22*. Compare that to the Stage 1, 30-34*. Think Buick wanted the Stage1 to shine in comparison to the base GS455? It would have been night and day. I have to ask Denny Manner about that next time I see him.
Yeah - for WOT, that's like only 20 degrees total timing from 3000rpm on, and 17 below that. That would feel pretty weak.
Stephan, take a look at these http://www.taperformance.com/proddetail.asp?prod=TA_2008D I actually have these on my 72 Buick with 70 SP engine attached to a magnaflo x exhaust
Ask Jason about the 72 GS350 he owned for a time before selling to Justin. It left rubber for the first time in it's life after Jason Power Timed it to 32*.
Its all about carburetor and ignition tuning. Once you get the tune dialed in, you'll be surprised at the difference.
Just another thought, does the timing cover have a cast in timing tab or a bolt on plastic one? IIRC, the '75 and up covers had the timing numbers up to 16 deg. CAST into the cast timing tab, earlier 350's only had numbers up to 8 or 10 deg.
That's an original cover. Buick stopped making that cover decades ago. Even back in the 80's, if you ordered a 350 timing cover from the dealer, you got a V6 cover with the plastic timing tab. I know, because I did. So even if it had a later cover, its not that much of a smoking gun.
That cover works just fine. 1975 you would see the plastic timing tab on 350s from the factory. Does not mean anything but a later cover. That harmonic balancer has seen better days, I would consider a rebuild by damper dudes or replace.
