Hey y'all I just registered on FTE so please excuse me if I'm askin a question in the wrong thread or something. I have a 1990 F-150 xlt lariat that I recently bought. It has a 5.0 H.O. I'm interested in doin some performance work on it but first I was hoping someone could help me determine the exact year of the engine. Any and all suggestions will b helpful thanks y'all.

 

Did the PO put in the 302 HO? if it has an HO that is a performance 302.

 

The guy said he wasn't sure what year mustang it came out of. The guy i bought it from got it on a trade and put it up for sale right away and I bought it. I'm sure it's a 5.0 H.O I just wanna figure out the year of it so I know when I order parts for it. It's the speed density version so that narrows it to 1986-88

 

The 5.0 blocks are the same , the difference is the HO has the HO roller cam and forged pistons up till about 93 when they went to the hyper pistons , i don't know how to tell what year it is , but the motor is the same if its speed density or mass air ......

 

How are you sure? Does it use the 13726548 firing order? What intake does it have on it the HO or the truck?

If the motor doesn't have the HO firing order you were duped.. sorry about your luck. If it does then it could be a true HO but it could also just be a later truck motor with a HO intake on it.

Upgrades:
If the motor has the HO intake on it take it off and put the stock truck intake back on... it's much better and the motor will make more power. Another option would be to use an Explorer intake but overall the truck version flows the most of all 3 stock intakes.
Next upgrade is the exhaust, if it's got the stock truck exhaust on it lose everything and install aftermarket headers and whatever you like behind it.. single or dual doesn't matter just don't go too big, this motor works better with smaller tubes because it really doesn't move much air so a single 2.5" or dual 2.25" with mendrel bent tubing.

 

It is indeed to HO I guess Ill just do more searching to find the exact year. It's already got headers to true duals out the rear.

 

There is no way to know the exact year of the motor Ford didn't label them as such, the best you can do is determine the relative vintage from the block casting number which is on the side down near the starter.

 

Only way to narrow it down is to
Pull valve cover and one pushrod, if its short then it's a roller cam...
With valve cover pulled, check cam lift
If its an 87-93 motor, there may be a fuel pump block off plate, remove it and see if its a roller timing chain. Some timing covers are cast with the flange just not opened up for pump arm though, so that may not work.
There may be a cast id number on the cam, if you have the intake off look through the oil drain back holes to see. Crank engine over slow to check.

Does the truck and car use a different harmonic damper. I know bolt pattern is the same but is the part number. Research that.

 

13726548 HO firing order on a mustang 5.0 HO motor

 

read the block casting numbers under the starter. the first letter is the decades # C=1960s D=1970s etc. yours will be an F. The seccond number is the year made. The third digit is model base design.