[KTL]

573 has a very long cure time so it will allow you a longer time for assembly of the case thru-bolts, o-rings and perimeter nuts. No change in strength when exposed to motor oil. Least amount of strength loss when exposed to gasoline. It's green.

518 has the fastest cure time which is about 1 hour in our application. It gets stronger with exposure to motor oil. Loses the most strength exposed to gasoline. It's red.

510 is the middle cure time, still long. No change in strength when exposed to motor oil. Falls in between the other two in strength loss when exposed to gasoline. It's pink.

Bottom line they'll all work. All are medium strength rating and perform well in terms of strength vs. temperature vs. time. Cure time is OK for all of them, since we all can typically get the case sealed within an hour (518) and the others allow you to take your own sweet time.

I'd choose 518 if it were up to me.