4.30:1 and Gov-Lock

[cosmick]

Along with my LSx swap, I have a good used Gov-Lock, and I'll be swapping in some used gears, 4.30:1 out of an Isuzu P'up, early '90s, 4-cylinder. Those used a 6-lug version of the S-10 axle, dunno if they're 7.500" or 7.625", but I probably won't be breaking them either way.
Otherwise, 7.625" 4.10:1 gears are common in round-body 2.2L S-10s, as are 7.625" 3.73:1. If I can't find 4.30s, I'll probably order new 4.56:1 gears.

[ssms5411]

Re: 4.30:1 and Gov-Lock

I was thinking about some 4.56 gears but I do get on the highway so I'll probably stay with my 3.73s. Let us know how the 4.30s work out.

[cosmick]

Re: 4.30:1 and Gov-Lock

I have experience with a mild 350 in an '88, that 5500 happily, and was a 700R-4 with a 3.73:1 rear. I liked the way that pulled, but this 4.8 is less torquey and more rev-happy. I'd like to end up with first gear being good for about 35 MPH, as the '88 was. I had a '78 with a 350, I put a 700R-4 in that, it had a 3.08:1 rear, on 235/60R15s, and even with the centrifugal advance not working, it did 25.1 MPG @ 65 MPH. A bit of math based on that suggests the 4.30s should manage at least 21 MPG, I'm really looking for 22. That QJ wasn't dialed in at all. 4.30s will un me about $35, cheap 4.56s would be at least $145. I have a better use for that $110 difference.

[cosmick]

Re: 4.30:1 and Gov-Lock

Change of plans: I'm doing a Ford 9.75" axle from an Expedition. Doing 4.30s and a Gov-Lock can still happen, for my '86, but isn't really any different, or thread-worthy, than anyone else's 3.73:1 / Eaton Posi swap.