help on gear ratios please

[Streetgliderx]

I have a 1986 Chevy K5 With a goodwrench 350/290hp 700r4 np208 factory geared 3.08, 4"/35's 65mph rpms in od 1300 roughly lookin at the small tach.


i want good highway manners and some more grunt i spend 90% time onroad but i like to crawl some light trails what gearing is recomended. right now i don't even use OD unless over 75 cause it shifts in and out for lack of torque

thanks

 

[NEK5]

I have a 1986 Chevy K5 With a goodwrench 350/290hp 700r4 np208 factory geared 3.08, 4"/35's 65mph rpms in od 1300 roughly lookin at the small tach.


i want good highway manners and some more grunt i spend 90% time onroad but i like to crawl some light trails what gearing is recomended. right now i don't even use OD unless over 75 cause it shifts in and out for lack of torque

thanks

I`d run nothing less than 4.56s..

 

[sweetk30]

my buddy has same basic combo on k5 blazer and had 3.08 then swaped in other axles with 4.10 and said now its a fun ride. so 4.10-4.56 is a good starting point. with over drive tranny the deepest you can get is best. lots have said this on here in the past.

 

[OffRoad]

4.10s would prolly be a good fit for you. some guys run 4.56 or even 5.13s with 35s, but that is more common with overdrive transmissions and guys who spend more time off road, then on-road.

(in before the guys with 35s, 5.13s, and O/D chime in to tell me how awesome it is. i bet it is, it sounds like a great combo.)

4.10s used to be the answer to 35s, but now there seems to be more of a shift to 4.56. if you have an O/D tranny and your buying gears anyway, there's no reason not to, the way i look at it.

4.10s are much easier to find in used 3/4 ton axles.

 

[Streetgliderx]

thanks fellas will 4.56 not push me to some serious high rpms on 65 70 highways?

 

[obijuan]

nope, puts you right in the zone.

 

[blazinzuk]

Ever gonna get bigger tires (you say no now but you have been infected now and it won't be long) Go 4.88s or 5.13s.

There are a couple of things you can do to your trans to keep it from shifting in and out. Also If you really want to find out the best gear combo that will net you the best mileage, put a vacum gauge on and drive around with it for a while. Max vacum = good fuel economy