kaz1961

I need to replace the dipstick in my 80. The engine is a crate with a 1974 block but the dipstick is on the passengers side, I thought the 74 blocks had the dipstick on the drivers side? Is it possible non Corvette 350 engines had the dipstick on the passengers side in 74? The problem I am having is the opposite of all the threads I found here by searching, the hole in the block is too small to accept the tube. I bought one labeled for a 74 and one for an 80 and both were too fat to fit the hole. I tried filing them down a bit but both of them broke when I tried to force them in. The dipstick that was in there was so tight that it also broke when I tried to remove it, I had to drop the pan and hammer it out. Any ideas would be greatly appreciated.

DUB

Can you use a set of calipers and measure the inside diameter of this hole for the dipstick....OR...if you have a large drill bit assortment...find the drill bit that fits in the block really good.

I can say that on an engine build for one of my customers...the oil dipstick on the right side and I used the dipstick for a 1985 corvette...it worked perfect.

DUB

65GGvert

You might try putting the new dipstick in the freezer to shrink it down a bit, them lube and tap it in while still cold.

TimAT

Grind a small taper on the tip of the tube. That will help get it started. And freezer or dry ice is not a bad idea. It's supposed to be a press fit.

kaz1961

Thanks for the replies. The casting number is GM 3970014 with the code E 6 74. The tube that was in there, that was super tight, measures exactly 3/8 with a digital caliper.

DUB

Thanks.

And what do your new dip sticks measure at???

DUB

kaz1961

They are the same size. I broke both of them trying to get them in. I have no idea how they got the first one in without it breaking.

65GGvert

Freeze it, put some grease on the end, have someone hold it in line, place a piece wood on top, and tap in.

kaz1961

Did all of that with the last one except for the freezing part. Will try freezing the next one which is on order. I also found this old thread with the same problem:

https://www.corvetteforum.com/forums...te-engine.html

If the freezing doesnt work I will give the ZZ4 dipstick tube a try.

7T1vette

The fit on that tube is line-to-line (same diameters) but can be as much as .002" interference. Any more that that will not be able to assemble (without abuse).

You can polish the block bore and the outside of the dipstick tube (where it mates), put a wipe of grease on it and in block bore, and freeze tube if necessary (dry ice will get the dipstick a LOT colder than your home freezer).

The key to the installation is to get the tube lined up well with the block bore before putting much effort to drive it in. Using a plastic or wooden mallet would be preferable to using a metal driver.

DUB

How are you trying to install it???? I have made a special tool that I use to get the oil dipstick tubes in.

I DO NOT hit on the end of the tube where your dipstick goes in. I use the flared portion of the tube where it will seat against the block when completed.

DUB

Bronze85

Ive used a 1/4 inch drive extension to drive it in . It doesn't distort the tube.

kaz1961

I was hitting them from the end, they go in part way but then stop and end up bending.

TimAT

I've used an open end wrench on the flared "bump" on the tube. Get it started, then drive on the wrench.

DUB

That is your problem right there. Once you get it started...you MUST or should contact the flare portion of the tube when hitting it to get it to go all the way in.

It appears that some use an extension or the box end of a wrench which seems to work when slid down on the tube.

My tool is quite different than that and actually slides down over the tube and contacts the flare of the tube so I can drive it in....and it extends outwards so I can hit the tool and still stay on the flare of the tube.

DUB