I was looking at the big block molded gasket windage trays that Summit sells and was wondering if anyone here has used one and if so, how is it? Also, do you have to use any sealer on it?

I redid a 440 six pack motor this summer for a local car show guy, it had one of those plastic molded ones in it with the stock crank, I reused it with the new 4.25 stroke crankshaft with no issues
I have since bought some to use on future projects
BTW, I do make and use my own crankshaft scrapers also

Did you have to use any sealer on it?

They work best on a cast pan with a flat mating surface.

Used one on a stock-type pan and did not have good luck because
of all the stiffening ridges on the pan did not match up well with the tray's seal.

This was a couple of years ago when they first came out, so maybe they
changed the design.

Joe

I used one on the 440 that we just rebuilt for my Dart. No leaks so far...I also used a new oil pan too.

https://www.summitracing.com/parts/sum-g2340/overview/make/chrysler

If you enlarge the picture in that link

I agree , especially with the area around the dipstick , not even close on the factory 402 Oil Pan

And other areas where only one of the two silicone rubber o ring material would seal along side the stiffening indentations of the factory oil pan

Didn't work for my 402 Oil Pan

I have one

It is in a 451 using a milodon pan.

It seems ok, except for the one mystery leak from one of the forward middle bolts in the timing cover.

Just a slow leak from the one bolt no matter how tight.

I like it and would use it again.