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Doing an engine swap and my original engine (351m/400)has the dipstick in the DS oil pan. New block has dipstick on the front of the PS block. Old block appears to have a weld sealing this hole ( might be some other sort of plug).
i had to swap the pans anyway since my set up is for a 4x4 and newer engine has a front sump for a 2wd truck.
any idea how to seal the hole in the block or any issues having both dipsticks? the dipstick tube hasn’t been installed but the shoulder around the opening is pretty narrow, making it hard to block this off with a bolt/RTV combo. I’ve blocked off a dipstick opening on the timing chain cover of a 289SBF before using the bolt/RTV combo in the past
I have two in mine. I don't see a problem with it. I'm sure it happened at some previous rebuild/swap. Just make sure at least one is accurate, and if only one is accurate make sure you use that one to check the oil.
With a 4x4 oil pan being shallow in front and deep more towards the rear, and a 2wd pan deeper in front, I don't see how a 2wd front dipstick even goes all the way in with a 4x4 pan? I haven't measured though, so maybe so?
I did block my 400's front dip stick hole (it's from a '79 F350 2wd wrecker) with a bolt and rtv as I recall, but it was a long time ago. I'll look again today.
I do know the original engine in my '77 4x4 was just never drilled for a front dip stick, it's just rough finish cast iron there.
With a 4x4 oil pan being shallow in front and deep more towards the rear, and a 2wd pan deeper in front, I don't see how a 2wd front dipstick even goes all the way in with a 4x4 pan? I haven't measured though, so maybe so?
I did block my 400's front dip stick hole (it's from a '79 F350 2wd wrecker) with a bolt and rtv as I recall, but it was a long time ago. I'll look again today.
I do know the original engine in my '77 4x4 was just never drilled for a front dip stick, it's just rough finish cast iron there.
I'll check the dipstick tube length again. maybe I'll cut it shorter and have a sawed off dipstick.
that explains why it looks like the front hole on my old motor looks like it was welded shut. I'm guessing all the blocks were cast w/ a hole and some were welded closed?
Mine is just not drilled in my '77. I've seen others.
Not my photo, but I think the lighter spot is just light reflection.
I blocked my 2wd block's dip stick hole with a long socket head bolt with a nut inside the block that is staked, then I see the orange RTV on the outside. Projecting the path, a dipstick would hit the oil pan and curve or bend, and never tell you how much oil is in the rear sump where the pickup is.
You can see that the lowest point in front is not much different than where the dip tube ends down in the sump .... 4wd pan on my 400. The tube has a tube nut and actually goes down in the pan, and the stick goes further. If using a front dip stick with a 4x4 pan, even a slight down hill grade would trap oil in front and give erroneous readings.
Now I'm curious. If I took this oil pan and blocked it level, plugged the dipstick hole, and put 6, 7, and 8 quarts of liquid in it, just to measure the levels on the side. I'll have to try that. I think I only have maybe 4 bolts on this one, just snug.
The original way that Ford blocked the front dipstick hole was with a small cup plug (small version of a core/frost plug). That is what was in my one-owner 1979 4X4 with a 400. I haven't checked for a while but I think they are still available for cheap from a Ford dealer or any decent auto parts store likely has them as well. Much better than using a bolt and/or RTV.
This got me curious. I went out to my rig and checked both dispsticks. Here's the part numbers on them. My engine has a rebuild tag from the '90s. Going off the dipstick numbers it looks like maybe the block came from a car and then they put the 4x4 pan on it. Interestingly the front/passenger side dipstick is quite a bit shorter than the mid/driver side dipstick. They read different too. The driver side (4x4 going from @tbear853 's pictures) Shows about half a quart over the high mark for me right now, and the passenger side dipstick shows about half a quart low.
Not 100% on 351M, but on a 4wd truck with a 460 (lets say on a common 460 swap into a 78/79 from a mid to late 80's truck). You have a rear sump oil pan, and it has dip stick on DS of the oil pan. But on a 460 engine out of a 2wd 78/79 you have the front of the block dip stick and a front sump oil pan. That is how you wind up with 2 dip sticks.
460 WAS not available (FROM THE FACTORY) with 4WD or a Manual Trans until 1983, then only in F250/350's.
Can you swap a oil pan yes, you also need to change the pick up tube/screen with a different location mount stud.
