Hello. Im building a 340 to put in a street car... a 78 Plymouth Arrow. I tried installing a 318 mock up motor to see what issues I'll run into and right away I see it looks like either a FRONT sump or maybe a mid sump (factory 340 style) will work.
Anybody done this? Any tips welcome.
I am considering taking a front sump oil pan from a dodge Dakota truck and splitting and slicing the two. Using the upper 2" from a stock 318 rear sump and grafting it to the front sump Dakota pan. If there is an easier and cheaper way id like to know. Thank you.

What was the 318 out of?

Have a look at Kevco oil pans.
https://kevkoracing.com/collections/mopar

The Sweptline trucks used a front sump pan.

If the front sump Dakota pan is for a 318/5.2, it should bolt onto the 340. You will also want the pickup tube.

I have a Sweptline front sump pan if you're interested. If you're not sure on the shape you need, remove the pan on your mock up engine and get the block located where you want it. Then cut pieces of card board to mock up the sides of the pan and sump to come up with the pan shape you actually need.

I used a factory car pan and this style of mounts

I love that style of mount as the motor doesn't MOVE, they provide good isolation, and they are inexpensive. My only comment would be to add an additional crossmember between the two for added support of the additional weight if possible. Looking good

isn't that the "universal" early hemi style bracket that uses flathead ford rubber mounts ?

Speedway Motors sells 32 Ford motor mounts that are a thru bolt design that are a way better choice than the ones that use plates of steel with studs attached and vulcanized rubber biscuits between two steel pieces. Studebaker used that weak style of mounts too, but many Stude owners opt for the 32 Ford style too.

Don't know on the hemi part but yes on the Flathead biscuit mount