91 F 150 engine swap.
Thread Starter
|
New User
Joined: Dec 2006
Posts: 2
Likes: 0
91 F 150 engine swap.
Could someone tell me if a 300 (4.9) 6 cycliner out of a 79 F - 100 (auto, 2wd) fit in a 1991 F 150 (auto 4wd). If so what other than fuel system? Bolt pattern same for transmission, etc. Engine mount change?
Any advice would be appreciated?
Any advice would be appreciated?
Elder User
Joined: Mar 2006
Posts: 627
Likes: 0
What engine was in the 1991 F-150? The 4.9 engine has the same bellhousing bolt pattern as the 5.0 and 5.8 and so the 4.9 would bolt up to a transmission that was behind one of those engines. However, the 4.9 (0 oz), 5.0 (50 oz post '81 I believe), and the 5.8 (28 oz) are balanced differently so you would want to use the flexplate/flywheel that was on a 4.9 engine. There are some other issues to consider regarding whether the 4.9 will fit. The '79 engine would not be fuel injection while the '91 is. If you wanted to stay carb you would have to remove the high-pressure efi fuel pumps and put a pickup in the tanks or use a regulator that has a return on it and replumb the fuel lines on the engine end. If you wanted to go efi with the engine and the truck was not a 4.9 to begin with, you would have to get all the efi components including ECU, sensors, and wiring.
A guy in one of the other threads said that the frame mounts are different and would have to be changed.
A guy in one of the other threads said that the frame mounts are different and would have to be changed.
Last edited by gustang818; Jan 4, 2007 at 04:21 PM.
Thread Starter
|
New User
Joined: Dec 2006
Posts: 2
Likes: 0
91 f150 engine swap
Thanks for the reply & help.
The engine in the 91 is a 4.9 with problems. It still has fuel system etc. All is still in tact. I had a wrecked 79 with a rebuilt Jasper engine & thought they would interchange. Will the head be the same with the EFI or do I need to swap heads since I have all the parts. I thought the basic block may be the only part that would be the same.
Thanks again.
The engine in the 91 is a 4.9 with problems. It still has fuel system etc. All is still in tact. I had a wrecked 79 with a rebuilt Jasper engine & thought they would interchange. Will the head be the same with the EFI or do I need to swap heads since I have all the parts. I thought the basic block may be the only part that would be the same.
Thanks again.
Elder User
Joined: Mar 2006
Posts: 627
Likes: 0
I don't think they changed the external engine/head on the 300/4.9 from 1966 to 1996; i.e. the bolt holes are the same in a '66 300 as on a '96 4.9. You would just have to compare motors and switch the different stuff over--manifolds, sensors etc.
Post Fiend
Joined: Mar 2002
Posts: 19,402
Likes: 38
From: Bonita Springs FL
One possible difference is the air injection into the heads that the EFI motor has. If you have emissions, you have to worry about it. To solve that, you could just swap heads.
If you are just swappin 4.9 for 4.9, then you won't need to go out and buy anything. While you have the motor out, I would replace as many gaskets as I can, the oil pump, and the pickup screen.
If you are just swappin 4.9 for 4.9, then you won't need to go out and buy anything. While you have the motor out, I would replace as many gaskets as I can, the oil pump, and the pickup screen.
Thread
Thread Starter
Forum
Replies
Last Post
ROBZ95XJ
1987 - 1996 F150 & Larger F-Series Trucks
1
Apr 22, 2012 09:13 PM
davbell22602
Clutch, Transmission, Differential, Axle & Transfer Case
10
Apr 5, 2011 08:41 AM
makemeknowit
Clutch, Transmission, Differential, Axle & Transfer Case
5
Sep 29, 2003 09:36 AM
