Looking for advice on 5.0 swap/build

Tylerhenry1998

New Member
Jan 4, 2020
2
0
1
23
Michigan
I have a 1991 grand marquis with the stock efi 5.0 it runs great but is pretty anemic I was looking at cams and found one specific for my non ho firing order but the problem is that it's my daily and really dont want to play around too much with it perfectly good engine. So I was thinking of picking up a junkyard engine to build up now my junkyard has plenty of great explorer 5.0s and a few mustang's and a handful of lopo efi 5.0s.
I was thinking of getting a town car efi and building it up because all the brackets and accessories would bolt right up and taking the gt heads and a mustang cam (not from junkyard) or an aftermarket cam. The other reason for the town car block is I feel itd be less abused than a mustang and maybe I could leave the bottom end alone
I know there's a few other things I'd have to do like dual exhaust mustang comp and maf swap?

I'm sorry for rambling I'm new here and have lots of questions like would all of that be worth it or just get a explorer motor and jam a cam in there and call it a day
 
  • Sponsors(?)


General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
20,321
6,892
203
polk county florida
Welcome to stangnet
Now about that non ho engine you got there.
A little research is needed to understand what you need to put a little kick in the sled.
The crown vic/grand marque is a heavy weight so you need torque to get it rolling. The engine in there is a low compression 5.0, like 150 hp and 265 lb ft of torque so not much you can do about it without a piston change, a short cut would be to find an explorer engine, they have a good bump in compression with a better head but the cam is the ho firing order. I believe in order to use the ho firing order some rewiring and a computer change is in order. This may be more than what you want to do for a daily driver.
Here is what I would do:
Get the explorer engine, this way you can still drive the heap while working on the engine, you can swap a non ho cam in, I would look into a custom grind but they get kinda pricey but I think well worth the extra bucks.
Use the explorer intake and throttle body.
Long tube header, you can keep the exhaust as is but you will need to add catalytic converters with an aftermarket h pipe or add a set of shot tube headers that bolt up to your head pipes (cheaper option)
Shift kit for the transmission
The most important part will be a gear change in the rear, it is the 8.8 and likely is a traction lock, I would do a 355 ratio but some would go bigger since it is an automatic.
Stick with the stock air box with a K &N filter.
That will get some pep in that sled.
Remember, it weighs 4000 lbs
 
  • Like
Reactions: 1 user

Tylerhenry1998

New Member
Jan 4, 2020
2
0
1
23
Michigan
Welcome to stangnet
Now about that non ho engine you got there.
A little research is needed to understand what you need to put a little kick in the sled.
The crown vic/grand marque is a heavy weight so you need torque to get it rolling. The engine in there is a low compression 5.0, like 150 hp and 265 lb ft of torque so not much you can do about it without a piston change, a short cut would be to find an explorer engine, they have a good bump in compression with a better head but the cam is the ho firing order. I believe in order to use the ho firing order some rewiring and a computer change is in order. This may be more than what you want to do for a daily driver.
Here is what I would do:
Get the explorer engine, this way you can still drive the heap while working on the engine, you can swap a non ho cam in, I would look into a custom grind but they get kinda pricey but I think well worth the extra bucks.
Use the explorer intake and throttle body.
Long tube header, you can keep the exhaust as is but you will need to add catalytic converters with an aftermarket h pipe or add a set of shot tube headers that bolt up to your head pipes (cheaper option)
Shift kit for the transmission
The most important part will be a gear change in the rear, it is the 8.8 and likely is a traction lock, I would do a 355 ratio but some would go bigger since it is an automatic.
Stick with the stock air box with a K &N filter.
That will get some pep in that sled.
Remember, it weighs 4000 lbs
Ok thank you now I've got a sense of what to do also I do have a mustang a 95 gt not just that grand marquis I thought of the grand marquis forum but all those guys tell me is "it's just fine the way it is it's not meant for speed" I agree to a point, 150 is just unacceptable I figured I'd get more mod advice here
Here's what I'm planning is a explorer motor with a mustang or maybe a more aggressive cam that'll work with the stock explorer pistons and heads an pushrods. The firing order isn't an issue I want to upgrade to a maf sometime in future and from what I hear the computer will plug right in other than the maf. Now the exhaust I was planning on dual for awhile I know someone who owns a shop that can get me a deal where I get kinda lost is the pumpkin gear I have a open diff I want something that is driveable on the freeway.
And as for the trans I keep hearing about shift kits and stall converters I'm not sure what they are or what they do but I really don't want to play with the trans I just had it rebuilt (apparently for the first time in its life it, was the tv cable bushing that grenaded the trans) it got about 1500 miles mostly high way. I'm not looking for anything crazy just something more than the gutless lopo 5.0
Also I'm retiring the car as my daily at some point its really undriveabe in Michigan winters