A couple months ago my father and I bought an aftermarket aluminum intake because the iron one was screwed. The full valley pan did not fit well underneath, but we had two old pans and a set of edelbrock gaskets lying around. I cut this prototype up because I heard of oil caking issues and I’m not looking to block the exhaust crossover.

I’m posting this so I can hear opinions on whether this will seal well, or if it will shift around and screw something up. Has anyone done something similar?

 

I wouldn't install something like you have mocked up without securing it in the engine.
Firstly I would say that you are fine just using the stock cam cover baffle and modern motor oil to control "oil caking" issues.
Secondly if you really want to install a baffle, get one of the aftermarket ones that replaces the stock cam cover baffle and uses the same screws to retain the shield. You can even make your own using these pictures as a template.

 

Even if you cut out the OE turkey tray I don't think it will work well because the sides will interfere with the gasket. You shouldn't double layer a gasket between the intake manifold and the lifter valley.

 

I haven’t used a turkey tray in 25 years, no caking, though upon reflection, I think most of the engines had no exhaust crossing over. On my better builds I have the underside of the intake coated with aerospace heat barrier and those definitely look the same after 20 years as the day they went in the engine.

Helpful? Not sure. FWIW, I would use the aftermarket baffle style if it will fit, along with composite gaskets..

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Once I get my bolts, it looks like I’ll omit the tray and hope for the best. Thanks for the input

 

I had lots of trouble with caking on my 350. Stock heads and intake, used fiber intake gaskets with no tray. I found a whole handful of burnt oil crud after less than 5,000 miles.
I also tried using Dick Miller's tray - that's the one pictured - and it still caked up. Splash will come up from the lifters - not just the hole over the cam.
Final solution was to cut all of the intake sealing areas off of the tray. Keep the tabs that go into the heads and a sliver to run along the bottom of the head. The fiber gasket will crush plenty to seal. Do make absolutely certain that intake lines up with the heads. Put it on without gaskets and use a feeler all along the top and at the corners. I had lots of problems with aluminum intakes not being machined correctly - intake surfaces weren't flat. And once the block is decked you can end up with a gap along the bottom of the intake/head surface that sucks in oil.