Blue Thunder intake with ram air?

[bluefatsback]

Thinking of ditching the factory cast iron 4V intake on my 1973 fastback with 351C. I have the factory ram air and lots of talk on this forum about how well the Blue Thunder intake works. The question is, will it fit? I don't want to modify the air cleaner. My car originally had a 302 and 35 years ago I switched it to a 351C out of a 72 fastback. I have read on this forum it will fit and others say it won't. So what's the real deal? How are you guys the are using it making it work?

 

[Big Red Mach 1]

If you don't want to modify the air cleaner plenum, then "No" it's not likely to fit in the way you will want it to. I have a Blue Thunder on my 73 with Ram Air. I used the shorter height 73 motor mount pedistals with the shorter height 71-72 mounts. This lowered the engine about 5/8" over a stock 73. Does it technically work at that point with a 4150 style carb? Yes. However, you will not have room for a carb spacer other than a paper thin one. To me, that wasn't desireable, so I modified the plenum. But honestly, you can't tell I did. There is another recent thread on here somewhere where we were going over this, and photos of mine and photos from another member or two that modified our plenums. I'll try to find a link.

 

[Big Red Mach 1]

This post had more to do with a 429, but I showed what I did to my Cleveland since the plenums are similar, and it's the same problem, of "how do I make it fit with Ram Air?" You will see im my posts that the removal of 1/2" from the top ring isn't visible. It just makes the gasket sit right down on the ring now insead of having a gap between them. I don't even think a MCA judge would notice.

https://7173mustangs.com/threads/trouble-with-ram-air-fitting-on-429.41768/

 

[bluefatsback]

Thanks for the reply. I really don't want to cut down the air filter housing. Knowing my luck, I would screw it up. The factory ram air is pretty rare, I wouldn't want to search out another one. I guess I need to figure out how much clearance I have between the air cleaner and ram air unit.Maybe use some Playdough?

 

[Sheriff41]

Thanks for the reply. I really don't want to cut down the air filter housing. Knowing my luck, I would screw it up. The factory ram air is pretty rare, I wouldn't want to search out another one. I guess I need to figure out how much clearance I have between the air cleaner and ram air unit.Maybe use some Playdough?

Use aluminum foil. Make a roll of foil to shape around the top of the air cleaner canister in place of the seal, close the hood on it, then open the hood and see how much the foil compressed.

 

[DAverkamp]

That’s a great idea!

 

[CandyRcode]

The air cleaner will fit with that intake. You cannot use the seal. I just removed one from a 71 M code I am working on. I will be selling the intake.