1984 is carbed 1985 is cfi and 1986 is f.i.The one way to tell on the 85 is the air cleaner,dual snokel and should say h.o. on it.You could get the numbers off the heads and engine and someone maybe able to tell from those.The 85 should have central fuel injection and aluminium valve covers that say powerd by ford and have a flat tappet cam and was rated at about 190 hp.
Did youy rebuild this motor ,why were you messin with the mains?Its not really a good idea to just start torquing things down.Most of the bolts on the bottom end clamp things down from bolt stretch and are only really good for one stretch,the mains are a little different bolt,but the same principal.
I have never heard of a main just coming loose ,without a problem thats not going to be fixed by torquing them down.