oldsygoody

In the next month or so I plan to change out the F 85's rear-end to a 3.42, put in leafs and new shocks etc. and while in there will drop the gas tank and attempt to fix the fuel sensor (? NOS replacement was in the cars glove box but don't know if it is reliable). Any idea if another, newer type sensor could be installed? New fuel gauge, not the stock one) will be installed also.

jaunty75

When you say "fuel sensor," we presume you mean "fuel gauge sending unit," right? If so, it should be too large to fit in the glovebox, so I guess we really don't know what you mean. I've never heard of a fuel sensor. Can you post a photo or something?

By the way, what year F-85 is this? They were made for quite a few years.

joe_padavano

The resistance of the sender must match the gauge. Depending on the year of your car (which you haven't told us), your factory gas gauge is configured for a sender with either a 0-30 ohm range or a 0-90 ohm range. A "new fuel gauge, not the stock one" could be configured for any resistance range sender. You MUST install a sender that matches the resistance range of the fuel gauge.

oldsygoody

Thanks, here's a photo of the sending unit. And the car is a '62 F85 Deluxe Coupe with engine and trans mods but nothing else so far (but not looking so deluxe at present). Small photo album is up. Unless the (pictured) unit is for something else, I believe it should replace the non-functioning one in the tank at present, right?
Reading Joe P's reply, I also know that if I change out the gauges I will need a sending unit to match, or vise versa but that's down the road aways. I found that out by hooking up another gauge to the current tank unit wire and it pegged at 'full', with an empty tank. And, yes, it was grounded.
https://classicoldsmobile.com/forums...1&d=1405707548

joe_padavano

That is an aftermarket sender, not a factory one. I have no idea if it has the right resistance or the right amount of travel for the tank in a 62 F-85. The stock sender is integrated into the fuel outlet unit on the tank. If this sender somehow happened to have the correct throw and resistance for your car, you'd still need to cut a new hole in the top of the tank to install it. Note that there are baffles in the tank and this sender would need to be oriented to clear them and still provide the correct float travel. Here's a photo of the original sender (note that on this one, the outlet tube is bent incorrectly).

1970-W30

I suggest you take a peak under your 62, the 61-63 F85 used a unique setup in the rear as far as the rear axle and coil spring suspension setup. That and the fact that it has a unibody(no separate frame) combined with the two piece driveline set-up make it extremely difficult to change out the rear end with one that would accommodate a 3.42 differential gear. That is unless you have advanced fabricating and body modifying skills. The only stock ratios available are 3.08, 3.23 and 3.36. You might look for a 3.36 rear end. It is a common ratio used for the 61 to 63 F85s.

oldsygoody

Thanks Joe and 'Jaunty'. I'll wait until the tank is dropped, during the rear-end work, to put in a sending unit to match new gauges. Regarding the back end work, a family member, quite experienced with under body/suspension work is providing the major work and has already measured/checked the geometry for leafs/coils/?new air shocks (don't know if the current ones hold air). And, with regards to Joe's previous answer about the weight of the 283 compared to the stock aluminum engine, new and beefier coils are going in the front. Regarding the 3.42, I mainly want to be able to put my right foot down (quickly) and not have my rear-end blow off! At the same time would like to also be able to go on the freeway a bit at not too high rpms, although I know the 3.36 would be better in that regard. As an aside, my family member has a relatively pristine '62 Skylark languishing in his garage. Just found this out.

1970-W30

Please let us know the part number or where you are getting the beefier front coils from. Stock coils from Kanter is the only thing I have found so far.

oldsygoody

Will do. Still looking at spring rates, front and rear, with an eye toward what stance I want the car to have. Also still don't know if the current rear air shocks hold air well, but will have compressor soon. I will take photos of rear and front before and after, leaving out the expletives.

joe_padavano

I can't say that I know what you mean by "blow off", but steeper rear gears will make it easier to spin the tires, so if that's what you mean by "blow off", you're going in the wrong direction.