I just picked up this manifold for my 55 project. It looks like someone cut it apart and welded it back together. Do you think it is to lower the plenum area? I was told it was on a 327 is this something thay did back in the day? Or did somebody needed more room for the air cleaner? Any help would be appreciated. Thanks Ron
Most all of them have the carbs place at an angle like that. My guess is they took out plenum volume. It was really common on the earlier tunnel rams as they had an ever larger plenum. I've done several of the early plenums, and usually never found it necessary on the style like your is. Usually it is to gain velocity/signal to the carbs. Personaly, this style of intake would never need that type of work. The eraly ones, I think wasa tr1y were just a huge square box, and those almost always benefitted from plenum reduction and or mods. If the engine was built with this style tunnel ram in mind, then this mod would have hurt performance on this intake. They were and still are one of the best tunnel ram desings. Personally, I'd look for an original top...I think there will be some issues with this one having the plenum shortened up as much as it is. Have fun and good luck.
Wow..that looks just like Bill "Grumpy" Jenkins' manifold from Grumpy's Toy IX. (1972). It was on a 327. http://www.hotrod.com/thehistoryof/hrdp_0706_10_historic_hot_rods_performance_engine/index.html
close but not quite. The one on Grumpys 331 had the carbs mounted sideways, and the plenum was not as short on his either. There was obviously a lot more time/craftsmanship taken on Grumpys as well. Still, if the op's doesn't have any vacuum leaks and there isn't too much imbalance/turbulance in the plenum it should still be ok. If it doesn't work right or is tough to tune, you can always replace the plenum with one not modified.
looks like they cut the top part of the manifold in half and welded it to the bottom part of the manifold i have a similar one but its a 2 part manifold it can be used as a single or dual maybe they had clearance issue and need to modify it ..just my 2c