Question about engine swap
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Question about engine swap
Hey guys, i'm new to the site here. I recently bought a 94 F150 5.0 4X4 with the motor having low to no oil pressure so that motor is coming out. My question is...I have found a rebuilt shortblock out of a 91 F150 5.0 for a pretty good price, I have been reading on here and understand that the 94 is a roller motor with a 351 firing order and the 91 is the 302 firing order. From what i've gathered, i can put my cam and lifters into the 91 block and be good to go. I haven't seen the 91 motor yet, is it a roller and will this work no problem for me? Thanks for the help and this site is amazing!! ~Chris
Cargo Master
Joined: Jan 2004
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From: Cook Forest and Irwin PA
are both speed density? if so just make sure the plug wires are in the right sequence and away you go. If the 94 was a MAF/sequential then the cam change will be needed if you really want the injectors to be timed with ign. (hey, in the 91 only 2 injectors were timed right. When you pop the MAF update on a SD truck, you get 4 right. Cam it with a 351 order cam and you get all 8
Post Fiend
Joined: Oct 2003
Posts: 6,214
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From: New Jersey
The firing order of the distributor matters, obviously.
With speed density, you can use your old EFI harness on the newer engine and not worry about it. The firing order will be slightly off but it doesn't really matter. I've done this swap before with no major issues.
Plug and play. Just make sure you get the dizzy wired correctly
Use the wires off the newer engine so they are the right length.
With speed density, you can use your old EFI harness on the newer engine and not worry about it. The firing order will be slightly off but it doesn't really matter. I've done this swap before with no major issues.
Plug and play. Just make sure you get the dizzy wired correctly
Use the wires off the newer engine so they are the right length.
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Joined: Feb 2001
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From: atl
Easiest way to tell about the 91 being roller (I don't know about the trucks, just the stangs) is to look at the top of the lifter valley. The roller blocks will have two protruding threaded bosses to attach the lifter spider to. If it has these, take the old cam out, put the new one in (use assembly lube on the mains) drop the lifters in, put the dog bones on the lifters (should be stamed which direction the go) and bolt down the spider (use loctite). You will also need to use your distributor as well. A haynes manual wouldn't hurt either (if I had a penny for every time I have used it I could buy a room full of them by now). At any rate, good luck.
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Thanx for the help guys. I went and checked the motor out tonight and it IS a roller block so all is good. I also picked up a chiltons just to have for torque specs/wiring diags/vaccuum hoses/etc. Thanx for all the help~Chris
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