[Perry1977]

I have a chance to buy an '89 Mercury Grand Marquis with a 5.0L EFI and AOD to power my '65 fastback. I am still trying to decide between a 351w and a 5.0, but if I can get this car for a song...should I?

*Edit* - By the way, the car starts right up, runs fabulous and sounds very strong. About 119k on the car. No smoke from exhaust, and it didn't appear to be dripping oil from anywhere. It looks like a well-maintained, old-lady type of car.

Here's what I want to accomplish: I want a reliable, fuel injected, super-charged small block stroker motor that will push my car into the 12's or low 13's at MILE HIGH altitude (Denver, CO). I also want the car to handle well, and get 20 mpg on the highway. A tall order, I know, but from what I read it is not out of the question.

I remember reading somewhere here on the forums that '89-'93 5.0's are the best year to get to build a motor, but I don't know why. Here's the questions I have:

1. What year(s) should I look for when finding a donor motor/car (and why!)?

2. Can I put a manual transmission behind a motor that originally had an automatic in it, or are there any computer issues that will make the motor run funny?

3. Is it worth it to buy an entire donor car? I was thinking having all of the electronics, fuels system components, etc would help.

4. How much would be too much to pay for the whole car?

5. Is the AOD tranny worth a damn? Can it be built to handle the performance of a stroked/supercharged small block?

Any other info will be appreciated. I need to know in the next couple of days whether to buy this Merc as the donor car or take a pass on it.

Thanks a lot guys!

[Snake Pliskin]

I'll answer what I can. The motors you want are 89-92 because they have mass air and forged internals. The 87-88's are speed density unless it was a California car. The 93's have the non-forged internals. The AOD can be built to take abuse. The computer is different for a stick shift car. Donor cars are the best if they can be gotten cheap. The time you will spend tracking down brackets, bolts, etc. is incredible but a donor makes this easier. Sorry for the quicky response but I'm taking the wifey out to dinner and I'm getting that look.

[Snake Pliskin]

Whew, she went back to finish her hair. I got my fox for $750 running. If you want to do the whole conversion, you're wanting the whole car for engine, trans, cooling system, fuel system, AC, probably the 8.8 as well. I would look for a complete car. I'm not sure how the Merc would work but I wouldn't think it would present anymore of a problem than using a fox mustang. This isn't the gospel though, someone else smarter will answer soon.

[Twister]

well, it is a speed density car and NOT a H.O. engine...I would pass, look for a Lincoln Mk VII LSC

[Perry1977]

Originally Posted by Twister

well, it is a speed density car and NOT a H.O. engine...I would pass, look for a Lincoln Mk VII LSC

What's the difference? Does it matter that I will be using new crank, rods, pistons, heads, etc anyway?

[74stang2togo]

If you're going to change much of anything on the engine at all, you'll need to have mass-airflow EFI. The Grand Marquis uses Speed-Density EFI, which would have to be converted. Twister's just saying you should get a better donor car for your parts because you'll be doing extra work and buying extra parts just to make the Grand Marquis stuff work. Another thing is that the Grand Marquis upper intake manifold was probably backwards compared to the Mustang upper (as most non-HO uppers were.)

[Perry1977]

Ahhh, okay, that makes sense. I have never built an EFI motor, so all this is pretty new to me. Will the mass airflow stuff on an H.O. work well with a supercharger, or will it restrict it too much? Is there also a difference in the computers between the two as well?

Thanks for the input guys, it's very helpful. Looks like I will take a pass on the Merc.

[Snake Pliskin]

Mass air gives you the ability to modify and your computer won't freak. Mass air is adaptive to anything you can do to your motor. Yes it will work with a blower.