Shocked by Dyno Results - 1990 Mark VII with 5.0 HO


New Member
Mar 12, 2018
Hi everyone, I'm looking for some opinions and help. A few months ago I had my 1990 Mark VII LSC run on a mustang dyno and as far as I know everything was calibrated correctly. Now, having a built AOD which likes to downshift under pressure the guys had some trouble finding a sweet spot in 3rd to run it up, but after 2 pulls the results were shocking. The car made 230.9 HP at 4490 RPM and 290.5 Lbs of torque at 3169 RPM at the rear the conversion for 20% drivetrain loss in the AOD and that's 288 Horse and 363 Torque...even if I lose 15% with the trans that's still 270 horse and 341 Torque at the motor...

So here's the thing. My car is a 1990 Lincoln Mark VII LSC with its original 5.0 HO, blueprinted original AOD, Stock exhaust, and 3.27 Traction-Lok rear. As far as I know, the motor has never been tempered with. I have had it resealed and tuned up, but myself and the previous owner do not know if anything else was done to it in its life but we are sure nothing has. So, this leads me to my this even possible? I don't believe so...I don't like to be a Debbie downer but I find it hard to believe that somehow I have some miracle 5.0 that makes 50 horse over factory numbers. The other issue is that when timing 0-60 in the car before the dyno, and before the tune up, I got just around 6 seconds...not exactly that but it wasn't 7. The things with that is the stock 0-60 for a Mark VII is around 7-7.5 seconds, 225 Horse with a weight of 3740 pounds. Now, doing a quick simulation mathematically, my car weighing exactly 3745 (I weighed it at a recycling center weigh station) and using the apparent 288 horse it would have a hypothetical 0-60 of about 6.1 seconds...which is close to what I timed with a chronograph a while ago...

I have asked around, my mechanic, other Mark VII club members and friends, and nobody can honestly tell me what I'm looking at here. To make matters worse though I do not believe the results, there are still a lot of guys that believe that these results are actually accurate and I have a very spunky 5.0... I do plan on building it, doing a cobra motor clone with all the trimmings, smog delete, O/R H, Venom 250s and 2.5" pipes...but before I do any of that I need to figure this out.

So, is this possible? Do I somehow have a miracle motor? I would like to say I don't, but theres a lot pointing towards it being so...and unfortunately I won't be tearing the motor apart until body work and paint are done and summer comes so I can drive the 88 since my 90 is a daily. Like I said, I find this really REALLY hard to believe...either way though I do have a dyno sheet saying its so for bragging that's not bad even if those numbers are 100% false. I may have another chance to dyno in May or so but its not set in stone...this would be a dynojet...but until then I have no clue what I'm driving anymore...


Walks Into Lift Arms at Work
Mod Dude
Mar 7, 2002
If you didn't buy it new, you may have improvements to the engine that you don't know about.
I had a Mustang II that was much quicker than any 139hp car should be. An engine teardown later on revealed that the 302 that still sported the stock 2bbl carb and smog gear was bored .040 over with flat-top pistons and milled heads.

Similar threads