I've a set of these manifolds from a '79 mustang. I've been planning on using these on my "Out w/ the 6, In w/ the 8" project. Never thinking they wouldn't work, at least not untill I've read about all the fitment problems you guys have had...Anyway, have any of you used old mustang, late 70's-early 80's, mustang exhaust manifolds? ExhaustL.jpg ExhaustR.jpg Thanks, Dave
Hi Craig, I always value your advise and you are always helpfull. I'm interested to know...These look very close to Mav manifolds with the end, instead of shooting straight out back, just slightly bent downward. What do they hit? It looks like it would help rather than hender the way they bend down. I'm sure you're right. I, just, am one of those guys that really like cast exhaust manifolds, and the Maverick ones are just...not that great. Thanks, you guys are the best. Dave
https://www.youtube.com/watch?v=QCrm405AMg0 http://www.cjponyparts.com/exhaust-manifold-pair-289-hi-po-1965-1967/p/EXM4/
The driver's side one appears that it would hit the steering gear box. It is a tight fit on that side.
Brick, I like the hi-po manifolds but they're larger than the mustang manifolds in the picture.Will these fit a Mav or are the links purely for my viewing pleasure? I'm leaning towards Craig's advise and gonna chase Maverick manifolds. David
You ever looked at the O.E. tubular manifolds ? 7 HP? In your dreams. Those are no better than the ones Ford used on the Explorers. They've got more pinch's than the proverbial "dirty old man"
Once you compare the main differences between those two manifolds that's a piece of cake to achieve those gains. And that's likely just an improvement rating for a lightly modified combo(typical alphabet cam, maybe intake, bit shorter gear, etc) .. not a hotter headed high-rpm/high-flow induction combo. There's easily more than 25 horse there if you're really pushing the motors air flow up against the collector sizing of a stock log manifold. IIRC.. reaching over 2 inch diameters is pushing it. Look closely at very restrictive log style manifolds and compare its dimensions and internal volume to a tube style manifolds significantly longer primary tubes(maybe 500-1000% longer on some primaries?).. and then take collector flange dimensions into account.. it doesn't take a dyno to figure out potential airflow improvements they may offer. Having modified everything from cars, trucks and Cobra Jet pieces through the years.. I can tell you the pinch/choke point lies in the collector diameter and back towards the middle to third cylinder of the manifold. Simply not enough material there to work with and you'll only get so far grinding away for flow improvements.
I doubt any of you have actually looked at the O.E. tubular manifolds. Take one and compare it side by side with a typical iron manifold. There's little to no difference, actually most of the iron manifolds have more internal volume and volume at the port.
I have many times. Which is why I commented so heavily on the matter. I'm not even going to go round and round here as the differences are massively obvious even to the untrained eye. The CSA of both designs are hugely different as seen here. Red lines are the pinch points to be most concerned about with iron manifolds. There is simply not enough material that can be removed to match the tube style manifolds and I've certainly tried to find it to the point of eventually cracking them. Now that I think about it more.. and for anyone who really cares about such things relating to airflow through an engine.. it's worth mentioning that pipes with twists and constrictions are not losing the flow that many will initially think they do based on visual inspection. This is because the constriction is only going to drop flow in proportion to its % of the constriction.. or reduction in CSA(cross sectional area).. multiplied by the OVERALL LENGTH of that same CSA constriction. Don't ask me for the math.. but it's out there to be had if you look. So, by those rules.. constricting a pipes internal diameter to 50% less of its original CSA will NOT drop flow by the same proportion. A heavily squished pipe still always beats a pipe similarly sized along its full length to match the MCSA(minimum cross sectional area).. or "pinch point".. of said squished pipe. Hotter and much faster exhaust gasses move around obstructions pretty well compared to an induction system.
