1978 Suburban 350 dipstick/oil level

[jddenham]

I bought this vehicle last summer for $800. It seemed to run smoothly, had 4-wheel drive, and a tow hitch.

The owner of the vehicle two owners before was in the auto body business and outfitted it with a 1991 front end and interior.

At some point the motor was replaced with a used school bus motor.

Finally to get to my question:

I changed the oil and there was only about 3 quarts in it! The dipstick showed full or maybe 1/2 quart low.

I changed the oil and filter and put in 5 quarts, ran it, and checked the level, expecting to be a quart low or so. It showed about a quart over full.

I'm assuming that the dipstick is inaccurate possibly due to the motor swap and related hardware. I added a little bit more oil (appox 6 quarts total) and am calling it good.

Any other explanations that I might be overlooking? I warmed the motor up before draining the oil - so that shouldn't be an issue.

If anyone has any other ideas besides an inaccurate dipstick let me know.

James

 

[roscoe]

Re: 1978 Suburban 350 dipstick/oil level

Our 1987 GMC van can from the factory with an inaccurate dipstick.

This caused the service station to overfill the oil by approx 1 qt. for the first several oil changes.

Took it back to the dealership and they compared several dipsticks with ours.
The full mark on ours was in the wrong place.

 

[ZmOz]

Re: 1978 Suburban 350 dipstick/oil level

Is there any kind of dent or odd custom work on the oil pan?

 

[dolluper]

Re: 1978 Suburban 350 dipstick/oil level

You should be looking at 4 quarts imp when you change oil and filter,so 4.1/2 american quarts unless the pan is oversized

 

[QC]

Re: 1978 Suburban 350 dipstick/oil level

Related side note. On many Caterpillar truck engines the dipsticks are sold unmarked. The correct procedure was to drain, change the filter, and fill 1 gallon low (remember these are 40 qt. pans), run it, mark the stick, that's your add mark. Then add the gallon, recheck, that's the full mark. This is because there is no telling what angle the engines sits and modifications a vehicle OEM might do once they get the engine. Think about a cabover when the dipstick goes all the way to the front of the truck and sticks out the grill . . . Sorta like your super modified Suburban

ZmOz makes an excellent point though, a mod to the pan voids this whole discussion . . .

 

[jddenham]

Re: 1978 Suburban 350 dipstick/oil level

There are no mods or dents in the pan. I have a total of 6 quarts with a std size filter. What can happen if it's a half to full quart over full? I sure don't want to blow a crank seal or something. Oil pressure gauge hasn't shown any noticeable variances.

The dipstick is super long and has straps bolted to the a/c compressor bracket. I think I will get an aftermarket std replacement dipstick and see how I end up with it.

Someone said 4 quarts plus filter for a chevy 350? I thought it was 5 plus filter, it was in my old hot rod(1984 Firebird with 1973 350 4-bolt out of pick-up truck).

 

[QC]

Re: 1978 Suburban 350 dipstick/oil level

The worst thing that can happen is that your crank actually hits the oil as it revolves, ever made whipped cream? Beat egg whites? You're better off a quart low than a quart too high.

350 oil capacity