I’ve been meaning to ask. What is the correct part numbers for 1970 455 Exhaust Manifolds? Would Stage 1 have a different part number set? Or were they all blanket numbers for multiple years. Reason I’m asking is: My 70 GS Stage 1 – not numbers matching – has driver # 1233451 and passenger # 1383648 which is connected to 1972 Heads – Is the passenger incorrect for my 72 head? For reference, Have a 70 Electra 455 junk yard motor that has driver # 1383899 and passenger # 1383648. I’ve seen others list driver # 1233451 and passenger # 1238094 instead as a combo – What year is this correct for? Then there’s this list I’ve seen in a thread on V8 which makes me think the 1383648 lists 400/430 motor is a typo and should be 455. Thoughts? Thanks!
Thanks for the pictures. Since these part/casting numbers cover multiple years, Does anyone know what year these manifolds I have were made? driver # 1233451 and passenger # 1238094 One shows 307 and the other 315 which what I gather is the DAY they were made. So puts them in November time frame. The time stamp has a 2 next to it which I think means second shift. One has a time of 7 and the other 9, so if the 2 is for second shift, the time is PM. Which matches what Frank has above. His show a 1 and a 2 by the time dial. and both don't have that one drop, two drop indication for shift either. The 209M doesn't follow the date code in the "code book". It shows letter than numbers. And M would be December which is ruled out because of the 307/315 day made number. Thoughts?
This photo was posted in another thread and shows that the1233899 manifold has a slightly different appearance than the 1233451 manifold which is a '71-'74. I'll compare my unrestored '70 Stage 1 to my unrestored '72 Stage 1, to verify is this holds true. I'm certain that both have their original manifolds.
Just following up to see if you were able to check you 70 & 72 stage cars. Thanks! and I saw these on the site which are listed as 70’s which look like mine. https://www.v8buick.com/index.php?threads/1970-455-exhaust-manifolds.392014/#post-3469016 I wonder if that difference shown above was between GS and big cars motors and not for years. I want to make sure I advertise correctly as I’m thinking of listing them for sale.
Sorry I didn’t respond sooner. Yes, I compared my cars and they matched this phot0 exactly. The ‘70 is straight across the top between #5 and #7. The ‘72 model has the extra material between #5 And #7. The cars are a ‘70 GSX Stage 1 built April 1970 and two ‘72 Stage 1s built August ‘71 and March ‘72. All are original, unrestored cars with all matching numbers drivetrains intact and I’m certain they are correct.
According to David Walkers, GS By The Numbers 1970: Left casting is : 1233899 Right casting is: 1238094 Other acceptable casting numbers for 1970 455's are: Left: 1233451 Right: 1383648 I hope this helps.
