5.0 build in 1990 Grand Marquis

[MjRock441]

with a stock intake and heads, messing with the MAF doesn't do much. The ignition system (in good condition, new ford wires, etc.) is also pretty good stock.

I've heard mixed results on spacers.

If you can, I'd put on some headers (ideally aftermarket and paired with 2.5 inch exhaust). Anything shorty and unequal length for 79-95 mustangs will work, including the stock mustang headers, but you will need to modify the downpipes. The mustang headers don't quite exit where the stock panther manifolds do. You may also have to change the O2 sensor wires, but a more EFI-savvy person will have to fill in the details on that.

Do you know what rear gears you have? If it's not a limited slip (tag on the diffcover will have an L in the code) I'd look at adding that, and if your gear ratio is numerically lower than 3.27 I'd certainly look at getting higher numerical rear gears.


IMO the restriction point on these engines is (in order) low compression and poorly flowing heads, crappy exhaust manifolds, very mild cam. Then for the rest of your drivetrain the numerically low rear end gears and low stall-speed torque converter also hurt your get up and go.

I'd also not consider your exhaust "done" or optimized because you have no converters and some free-flowing mufflers. The 2 inch stock stuff is still a restriction, especially once you open other stuff up and if you have crush-bent replacement piping. Not a huge priority but something to consider.



Oh, and welcome to the site! I hope you enjoy it and stick around to post more pics and info about your car.

Hey, John.....I put some pics up. I got this car for $500 worth of yard work in 2009. The odometer had stopped at 79k back in 97, based on an old oil change sticker. I've put at least 100k on it. The best $500 I ever spent. The rear end is a limited slip with 3.55 gears. Gotta go to work, but look forward to future communication.

Mj

[MjRock441]

There it is!

[V8GrandMarquis]

Hey, awesome Merc. How did you get the shelby caps on the turbine centre caps?