5.0 vs. 5.0 H.O.

Anyone know what the difference is between these two motors? I'm asking since I have a Merc Grand Marquis 5.0 to put in my 1966 Mustang. I bought the Merc thinking the 5.0 was a high performance engine, but it isn't "High
Output." Runs well though. I do know the firing order is different.
Gary in NC
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Gary, Pretty much the block is the same. Everything else is different. You didn't mention the year, starting in 1986, they both have roller cams, different roller cams, but almost every other part except the cap, rotor and wires is different.
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Hmmph. I didn't know all that was different. When I looked and saw that the firing order was the same as my 66 motor, I didn't know where to start as far as differences. My motor/trans is a 1990, AOD trans. I'm glad to hear it is a roller cam engine though. Is there a website to look it up? Thanks for your help.
Gary
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There is some info here about converting http://www.coolcats.net/tech/advanced/ho_conversion.html
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Thanks a LOT for that link. I'd have never found it on my own, I'm sure. One day I'm sure I'll want more horsepower and I'm sure I'll use this info.
Gary in NC.
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I could be wrong but IIRC the 302 didn't get a roller cam until about 1990 or 91. Bob
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Your on the correct path, the HO used in Mustang / Capri; Continental and Mark VII got the roller cam in 85. The base 5.0 did not.
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Yes, the HO got it in 85, the non-HO got it in 86.
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The main difference is the cam, which gives the HO engine the same firing order as the 351, which means you will need a processor for the HO. Depending on year there will be other differences like heads roller cams and intakes.

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