i ran into a problem a while back, and forgot about it until it came up again
moroso list a gen 5/6 pan #20413 for chevelle chassis, clears 4 1/4 stroke(540) however, the pan hits the steering(drag link and tie rod grease fittings-i called moroso and they said it was a mistake, use the 20411, and it will clear 4 1/4 stroke-they exchanged it, and the 20411 fits great-they never corrected the catalog, and i know some people used the 20413 pan and lived with it(raised the engine, beat on the pan)but the 20411 is the best solution-hope this helps someone(its amazing the guys @ moroso tech knew imed. what the problem was!!!!!!!!!!!!)

Thanks for the heads up! I see that the 20413 is listed that way in the Summit catalog too.

I have the 20413 on my 65.Had to thump it with a hammer to clear the inner tie rods.The Tech guys knew it wouldn't fit when you called, because enough people had already complained.Did you have oil filter issues ? I did with 2" primarys and had to use a remote filter kit.

I had an opportunity to buy a 20411 pan on ebay. The seller's pic didn't look like the one on Moroso's site. I called their tech line and was told that what he had was an older 20408, which the 20411 superceeded, and that it definately would not fit my 4.25 stroke Gen VI in my '66. The tech guy told me that it would only fit '68 and up and that their 20413 was definitely the right pan for my application as it had the notches to clear the stroker crank and the right sump contour to fit the '66. I hope this helps shed a little more light on the topic.