trillizo_y_uno

According to Mustang by the Numbers, in 71 there were only 26 Grabber Lime Fastbacks with White Knit Vinyl Decor. No way to know for sure, but I'd be willing to bet the majority of those were Mach 1s.

I think the fact that this car is NOT a Mach 1 makes it pretty unique and cool. Based on the YouTube videos, it's probably not worth saving. But if Trevynd had the means, it would be an awesome car to restore back to original. Just sucks it wouldn't be worth a fraction of the cost it would take to restore it.

Yeah, it's in really nice shape. I purchased it used several years back, but never ended up installing it. I went with a different manifold. I'm not certain on shipping costs, but I can't imagine it would be more than $50. I think $250 shipped would be a fair price.

Both of my manifolds had leaks where gasket material had blown out. I thought about swapping over to headers. But as others have mentioned, I didn't want to deal with the prospect having to constantly retorque the header bolts. Instead, I decided to keep the manifolds. I had a machine shop resurface manifolds so they would mate up true to the heads. No regrets.

HA, I think you have this backwards again. Knock sensors are there to detect detonation and retard timing if detected. For example, if your car calls for premium fuel and you put in 87 octane fuel, it may cause the car to detonate. The knock sensor would detect this and retard timing as a result.

I think you might be looking at it backwards. It is true that higher octane allows more timing advance. I don't necessarily agree you should advance the timing just because you move from 87 to 93 octane. Ideally you figure out the timing your engine is happy at and try to get it to run without detonation with the fuel you have available. With Clevelands, they tend to like a lot of initial timing. 16 degrees BTDC is usually a good place to start. However if your distributor is curved with a 15L advance slot, your all in timing will be 46 degrees, which is probably too much. You are better off running a 10L advance slot, for 36 degrees of all in timing. You also have to consider vacuum advance and the springs, which control the rate of mechanical advance.

I have one I might be willing to part with. I can post a few pictures if you are interested.

I am literally non-existent on the scene, but I might have to check it out one of these days. Most of my free time gets sucked up by my kids with sports, etc.

I'm going to have to check out NE Performance Mustang. I'm not far away from there, but had no idea they existed. Regarding your question, I'd probably test a small area with paint stripper to make sure it won't damage the plastic. You could probably also get the paint off with a pressure washer. Either way, be careful. The plastic finish is probably pretty brittle after all these years. As far as new paint, there are some plastic paints out there you can use. But it might be better to use a dye.

I'm curious about the inevitable failure, since as I mentioned I've been running the factory tach with a bypassed resistor wire for years without issue. We all agree the factory tach is nothing more than a glorified current meter. The more current goes through it, the higher it reads. Bypassing the resistor wire simply removes some resistance, thereby allowing more current to flow through it. From my observations, the tach reads approximately 150-200 rpms higher with the resistor wire bypassed. So my question is, how is bypassing the resistor wire dangerous to the tach at all? Stepping on the gas pedal, driving around, even adjusting the idle higher, would all have the same effect of subjecting the tach to a current increase. My point is, all tachs will probably fail at some point. But I don't believe the resistance wire bypass does anything to shorten its lifespan.

I've been running the factory tach with a bypassed resistor wire for years without issue. I think the assumption is that it will give up the ghost at some point, but it has yet to happen.

I would think so. Remember, 4V ports are huge and should be more than capable of flowing whatever your 408 can throw at it. My main point, there is something else going on here. You aren't falling off a cliff at 5K RPMs because of valve shrouding.

I would try to eliminate the simpler stuff first. Could very well be an ignition issue. What is your ignition setup? Is spark jumping at high RPMs? Is your spark plug gap right? Is spark getting blown out at higher RPMs? Do you have a carb you could quickly toss on for a dyno run to compare to the EFI?

Hmmm, I'm no expert. But as George Pence once said, "If you have an engine, equipped with 4V heads, that flattens out before 6000 rpm, it has a problem. Floating valves, collapsed tappets, valves sticking in their guides, carburetor secondaries that don't open, malfunctioning ignition, exhaust valves opening too late, somebody's pounded a potato up the tail pipe". So looking at our dyno sheet, I don't think your issue has anything to do with valve shrouding.