We are working on rebuilding our credit in order to obtain a home loan in the next 1.5-3 years. I was looking at the different scoring models today and noticed there are HUGE differences in my Fico 8 & Fico 5 scores. Can someone explain why there might be such a difference? Does the Fico 5 look at mortgage history more than the Fico 8? We have excellent mortgage history from previous home loans and excellent auto loan history, but I have a LOT of collections (like 15 or so, all very small amounts). We have just recently obtained our first credit cards to help build our scores. The scores are below. Thank you! 
Fico 8
EQ: 596
TU: 598
EXP: 583
Fico 5
EQ: 612
TU: 642
EXP: 641
Usually when we've seen FICO 04 and earlier (mortgage trifecta) much higher than FICO 8 was because of no open revolving tradelines; smaller hit for no open installment ones.
FICO 04 doesn't seem to count that as much, closed tradelines are nearly equivalent from what I and others have seen. I don't think there's any intrinsic difference in how they weight mortgage lines, certainly not to that extent.
