I am trying to solve a puzzle on a 68 RS Camaro Convertible 210hp/327 I've owned for 28 years and bought from the original family; when purchased it had 48K original miles. This is an early build car 09E and every single part on this car is either "born with" or replaced by me and the original parts are on the shelf - example, the original date code main bearings, pistons, rear springs, shocks, etc. Hell, it even has a correct date stamp in the timing cover which I didn't know existed until I bought this car. There is only one part that does not match and that is driver's side exhaust manifold, which was replaced in the late 80's due to a crack in the original. This car was delivered to the selling dealer in Wisconsin, which the car promptly went to Southern California.
I don't know if options have any impact, I'm providing them if it's a clue. The options include Powerglide automatic, power steering, power brakes, power top, factory air conditioning (especially weird for a Wisconsin car?), deluxe interior, gauges, reverse mount 8-Track, RS, and ultra-rare fiber optics vigilite option. This is a Norwood built car, engine stamp date code of 09-28
Here is the confusion. The right-side exhaust manifold, date coded 3 days before the engine build date and assumed original, is 3872730 - which has provisions for A.I.R. but has what appears to be factory plugs in the machined manifold. That manifold is typically paired with LH 3892683 to match A.I.R. provision. However, this is an automatic car, built in Ohio, delivered to a Wisconsin dealer. By all rights, that car should have LH 3892679
and RH 3840912, not RH 3872730.
So, what is the correct LH manifold to use for this car? 3892679 (book correct) or 3892683 to pair with what appears to be a factory installed RH A.I.R. manifold for a non-A.I.R. car?
I don't know if options have any impact, I'm providing them if it's a clue. The options include Powerglide automatic, power steering, power brakes, power top, factory air conditioning (especially weird for a Wisconsin car?), deluxe interior, gauges, reverse mount 8-Track, RS, and ultra-rare fiber optics vigilite option. This is a Norwood built car, engine stamp date code of 09-28
Here is the confusion. The right-side exhaust manifold, date coded 3 days before the engine build date and assumed original, is 3872730 - which has provisions for A.I.R. but has what appears to be factory plugs in the machined manifold. That manifold is typically paired with LH 3892683 to match A.I.R. provision. However, this is an automatic car, built in Ohio, delivered to a Wisconsin dealer. By all rights, that car should have LH 3892679
and RH 3840912, not RH 3872730.
So, what is the correct LH manifold to use for this car? 3892679 (book correct) or 3892683 to pair with what appears to be a factory installed RH A.I.R. manifold for a non-A.I.R. car?