So many "maybes" on here. There are 2 plastic cap makers that I know of that have good ones. Fortunately my supplier uses them.
There are lots of bad ones out there.
I havent had any caps with flash.
Not that many years ago casting flash was a huge issue.
Not so much anymore.
Viton orings are the biggest problem solver, harder orings will distort the caps over time, the oring needs to take up the flex, not the cap.
If you guys are dead set against China orings and other small items here are the choices.
Dont read the fine print, you wont like the facts, dont ***** about the price IF we can even supply USA parts, they are expensive. And keep in mind that even though we dont like it , its here, it sucks but not much we can do about it.
MAking a metal cap higher is not a good idea, inj line tolerance and inj brand difference is minimal but could pose a problem.
I recommend an old or new oring on top of the cap if they "ride up", not a problem if the hose is correct length and there is no "back pressure " on the system.
Ive sold hundreds of Install kits and only had one with a major issue and it was because the person used screw clamps.
Best way to distort the plastic hose nipple ever.
Oh,,Early hose is 5mm id.
Late hose is 7mm id.
And for the folks that complain about my kit price and buy the cheap one from pensacola or other sources. 3 of theirs equals one of mine that actually does perform as advertised.