3.8L rebuild oil pump

I’m rebuilding a 3.8L engine for my 62 e-type. I’ve rebuilt a few 4.2s and one xk120, but this is my first 3.8. I’m a bit confused by the oil pumps that are available for purchase, and the old posts are not making clear what I need to buy. I believe the 3.8L pumps were at one time not available, but are now advertised. Apparently 4.2L oil pumps can be fitted (?is this a bolt-up?) but the pickup tube diameter (and flange?) must be modified. If I can get an original style 3.8 pump, what is the advantage of modifying a 4.2 pump?
Please enlighten me if I am missing something in the equation.

I put the 4.2 pump in my 3.4 liter xk150. Higher oil flow was my understanding of the benefit. My oil pressure definitely improved. But also replaced bearings at same time. If memory serves, just had to glue a sleeve on original suction tube to mate up with pump inlet. No big deal. Otherwise just a bolt in conversion.

I don’t think you can buy a 3.8 pump period. What you get is either a 4.2 that requires you to add a downsizing collar on the input hole…or you can get the same where the collar has already been fit. If you look at the Terry’s website you can see a 3.8 pump for sale with the brass collar already fit to it. But it’s not a 3.8 pump.

Before buying a pump, I’d first measure the OD of your oil input pipe. If it’s 7/8" then it has a 4.2 pipe. Many have been changed already because 3.8 pumps started drying up 20 years ago. If that’s true then just order one without the adapter.

As to whether the pump actually physically fits, that’s a bridge you’ll have to cross when you get to it. If it doesn’t, I worked out a pretty simple modification by filing down the pier that the oil pan baffle bolts to. You can easily add an extra 1/8" of clearance that way and not change anything functional.

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So it was the baffle mounting height issue that was causing you the problems, Erica?

Yup it collided in two paces with the edge of the baffle. The combination of lowering the pier and peening over the leading edge in front of the pier allows it to sit flat without the gasket installed yet.

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Yes, Terry’s does seem to offer that 3.8 pump. When I spoke to them recently, they indicated that they had a 3.8 pump or a 4.2 modified to fit the 3.8 for more money. I’ll investigate further, but it sounds like I just need the 4.2 pump and do the mods as needed. Is there more than one quality 4.2 unit? I’ve just used the stock item on my previous builds, and this is going to be a stock, street motor.
Thank you

Just outta curiosity, is that 3.8 pump also advertised as a 3.4 pump?..they should be the same.

I just went on to the Terry’s site and he lists 2 pumps…one aftermarket 4.2 pump, and one “genuine” 4.2 pump, BOTH converted to fit earlier cars (3.4 and 3.8). This has been the norm for many years, actually.