Wheel size (offset) on a lowered '68 C20 ??

[KevinK7]

Just want to run this past the experts to see if I'm on track with regard to wheel offset for my planned setup.

The truck: '68 C20 Utility bed (396 BB, 4sp)

Lowering: I plan on going with Performance Online (POL) 2 1/2" front (8-lug) drop spindles (with Disc brake conversion) along with 4" drop coils in the rear (hence 2.5/4 drop).

Wheels: I plan to go with with 17x8" ('05 OEM Dodge) aluminum wheels with a 5.7" backspace (8"/2 + 1.7" offset=5.7 BS).

Since factory BS was I think 4.5"(16x6.5 wheels), I believe I will need to make-up 1.2" hence thinking I might need to ADD about 1" spacers.
POL notes that the (disc) spindles bring the front wheels out 3/4" (0.75").

Based on the above, what is your take on my need for spacers up front/rear?
I am thinking I might be OK up front with no spacers, but need to add (1"?) spacers in the rear (to line up with the fronts)?


As for...
Tires: Going to go with whatever fills the wheelwells best with the lowering and wheels above. Thinking in the range of
275-55-17 (6.0SideWall 10.8Width 28.9Dia) or
275/60-17 (6.5SideWall 10.8Wide 30Dia)


Note: The truck will otherwise maintain complete stock (C20) equipment. With the exception of course of whatever is necessary to update with the lowering (ie. shock relocation brackets, adj. panhard, etc)

[Mike C]

My short bed truck has 17x8 wheels with 4.5" backspace in the front and I think that's about perfect. I went with 235 55 17 tires in the front. I have 275 55 17 in the rear on 9" rims with 5" backspace. I have a stepside so less clearance to the inside so 1" spacer should be great for both ends.

[KevinK7]

The front backspace of 4.5 seems in the range of what was factory, so I'd expect that to be OK. Wondering at what point above 4.5 it becomes an issue (with the 17" wheels).

[Mike C]

Depends on the wheel width. It looks to me on my truck that tire would rub on the outside of the wheelwell before the inside in the front. But hard to say. Zero offset works well on my 8"/9" combo, but the tape measure is your friend. A reminder again my truck is a stepside and there is more room in the rear for a fleetside truck.