Thanks for the comments guys. Anybody on the forum have the ram air restorations manifolds? I'd be grateful for their input.
My 1980 TA has Ram Air III, D port manifolds from Ram Air Restorations. They were purchased from Butler Performance in June of 2015 with an engine build. Butler part number is RAR-RM20S for 429.95, price has gone up in 9 years. I looked online at Butler's web site and they no longer sell Ram Air Restoration manifolds. Ram Air Restorations is still listing the manifolds, but after Covid there have been lots of reports of back orders and slow delivery. There are other sources for RA manifolds but depending on who you listen to they are not as well made RA Restorations. Ram Air Restoration brags their manifolds have larger machined ports and flow better than other brands. Years ago, I saw a dyno comparison test saying RA Research manifolds flow almost as good as long tube headers with similar horsepower numbers. But I think the test might have been made without an exhaust system.
Only you can decide what is right for you and your car. I personally don't like long tube headers on a street car and question how much power gain you get from them when running a through a full exhaust system. Maybe shorty headers would be a decent compromise. Better flow than log manifolds, a lot easier to install than long tube headers and a lot lighter than RA manifolds. But I am not sure what's available in the way of shorty headers. It would be nice if more members would comment on their real world experience with headers versus manifolds.
My RA manifolds when I received them were bare castings. I sent them back to RA Restorations and had them ceramic coated gray color inside and out. They claim they run cooler coated, i am not sure. The reason I had them coated is I did not want them to rust. You can see the outlets are about 1/4" larger than factor RA manifolds.
IMG_3946 by
Lawrence Alexander, on Flickr
Bare uncoated manifolds mounted on engine, before ceramic coating and no gaskets yet.
IMG_3947 by
Lawrence Alexander, on Flickr
Picture taken today about four years later, no rust but instead of gray color they look kind of brown, still no rust though. The RA manifolds are big and heavy, changing engine mounts with these manifolds installed is a real pain, almost impossible.
IMG_3948 by
Lawrence Alexander, on Flickr
