[tekenaar]

The sprint manifold is a stock exhaust manifold, I believe it was on the 74 and up fuel injected engines. It looks like a regular manifold but doesn't have the heat riser/box that sits under and bolts to the carb. Do a search on the site here and you'll get tons of info about it. If you did a sprint manifold you'd have to get a new pipe from the manifold to the muffler because the sprint manifold isn't near as long as most headers I've seen for the Opel. It has a few advantages over a steel header. It lasts very long being cast iron, the flange where it bolts onto the head is the same thickness as the flange on the stock intake manifold, it flows as well or better than some of the headers out there. Also, the thing that has you looking for a new header, the low clearance from the pavement because of the collecter, is not an issue. I'm no expert, this is just what I have gathered from the info here and what motivated me to get one. Someday, I'll put it on. HTH

Actually, ONLY the '75 models had FI and the Sprint manifold here in the US. All the "commercial" headers for the CIH engines sold here had "flange thickness" problems and, since they were not "equal length" design, don't really perform any better than a Sprint with 2" exhaust back from the downpipes "Y" junction.