heater hose routing??

i think i have 1 bigger(5/8") and 1 smaller(1/2"), but on a 70 later engine and car they were both 5/8" hose. the funny thing is that it stopped leaking. i should have worded it better, it didn't blow, but started leaking when i was getting on the freeway, which by habit i leave it in second, punch it 1-2 shift at about 5400 rpm and then hold out to third till i feel like it.....about 5000 rpm. i do have it plumbed backwards to what suregrip and longgone have. but it has worked flawlessly. i did get about a 1/2 turn on the hose clamp. my buddys is plumbed how i got mine, so is dgc333's on his site.???? what happens if its backwards??