Here's a little background on a project of mine, my question is at the end. I recently bought a rebuilt 300 I6 from a 1980 F-150 my neighbor owned to replace the I6 in my 1987 F-150 2WD. The 1980 engine has the D5TE block casting number, and it has the dipstick in the PAN on the left side, and the truck had no power steering. The engine in my 1987 is original (with 335,000 miles) and has the dipstick in the BLOCK on the left side. I initially thought (and was told) that the blocks and heads were the same, however I initially noticed the difference in dipstick location, but it's not a big deal to me where the dipstick is. It did, however, tell me that the blocks were different, so I started looking for other differences and noticed that the 1980 does not have a mounting hole on the head for the power steering pump which my 1987 does. This means I will have to swap the heads in order to be able to mount my power steering pump. I thought I was fine at this point.

I popped the valve cover off the 1980 I6 to see just how clean the engine was inside, and I was very pleased. I was not pleased, however, to see that the valves on this engine have to be adjusted in a manner similar to a small block Chevy where you have to turn a nut down on the rocker arm mount to adjust the valve lash. Since I ground the valves in my 1987 5 years ago, I remembered that that engine has non-adjustable valves; the adjustment is done by the cam followers (lifters, to some). This is my dilemma, and here is my question: can I swap the 1987 head (with its non-adjustable rocker arms) to the 1980 block? If someone out there knows it is possible to do this, which push rods and which cam followers do I have to use, 1980 or 1987? Thanks!

 

The 80 model year undoubtedly had another mounting location for the power steering pump.

 

swapping an EFI head to a carb'd engine will require timing changes (fairly drastic) due to the "fast burn" combustion chamber. plus there are differences in the exhaust bolt holes (some are missing/added), etc...it can work but it will take some tinkering.

 

I guess I neglected to mention that, though I will be changing the 1980 block over to EFI, I will be using the 1987 head to do it, so manifold bolt patterns will not be a problem since the head I am using will be original to the truck, and I will be keeping the EFI. My biggest concern is that the two different valve train styles (adjustable valve lash on the 1980, non-adjustable on the 1987) will not allow me to swap the heads between the engines. I guess this is essentially what I am asking - can I put the 1987 head on a 1980 block and still have the valvetrain function, and if so, which cam followers and which pushrods do I have to use? Thanks again, sorry for any confusion!

 

Will the compression ratio change? I thought it did, but not totally sure. I know it's not recommended to use an efi head when going to carb. May want to search this forum for that, My 2 cents.

 

Just for the record, the short-block swap of the rebuilt '80 carbed motor was made to replace the '87 EFI short-block in my truck this weekend. Used the '87 head and rocker arms, but the pushrods from the '80 (they weren't as "gunked-up" as the pushrods from the '87, but they are the same length). Everything bolted right up, and the timing was spot on when we started up the engine. The only problem was there's no threaded hole on the '80 block for the knock sensor from the '87, so that sensor was just plugged into the harness and allowed to dangle.

In summary, the two short-blocks are mechanically identical.

Thanks for your responses.

 

Be careful of knock if the sensor isn't there to tell it to adjust the timing you might end up with damage!! I would take a nut that fits the sensor to a welder and have him tack it to the block in about the same area as the original, Maybe it will hear knocking maybe not it's worth a shot those piezo transducers are pretty sensitive! You could check if it works by putting a multimeter on it set to read milivolts and tap on the block it should put out some voltage with each knock!