Dip stick tube?

[Hawssie]

I know this going to sound stupid and easy to figure out but I am having trouble figuring out what dip stick tube to get for my engine. The truck Im working with had a 1969 307 in it. But it had a funny engine code that no one could figure out because it has a CE number that says it was from the early 60s originally a 383 and was an over the counter replacement engine I think. Anyways I am now putting in a crate motor 350. Its been sitting around on a stand for 6-7 years and I think was one of those 300-330 hp engines GM was selling back then that is the newer one piece oil seal block with the Vortec heads. Anyways they were really popular back then and maybe still are. I never dressed it out fully and now am. So I go to put the oil dip stick from the older engine into the new one and its diameter is to big. The older engine has a 7/16 hole and this one is a 3/8 hole. I looked up and down online on Summit but nothing is ever mentioned about diameters, just years and it seems to be all over the place. Is the new engine the typical size or is the old engine the typical size? It seems easy enough to order one for a "Small block" but I want to make sure Its going to fit.

[Roninwolf]

All small block chevys from 60's 70's and early 80's are the same dip stick they changed in mid 80's to one that goes into the oilpan.

[Hawssie]

I will just order one and see what happens but believe me I am not imagining this. I stuck a 7/16 bolt into the other 1969 truck block and it fits perfectly. The block in the picture which I assume is the normal one fits a 3/8" bolt perfectly. Figures I would have some weird deal going on with the CE engine.

[kcsa75]

Originally Posted by Roninwolf

All small block chevys from 60's 70's and early 80's are the same dip stick they changed in mid 80's to one that goes into the oilpan.

Do you know what the change was and/or how to tell the difference? I have a 350 crate motor that I'm told is the old design. I change the oil, put four quarts in and it tells me I'm full, even after I start it and fill the filter.

I started a thread a while back asking about length, but got different answers from different folks, which left me no better off than before.

Your post has me wondering if my dipstick doesn't match the block.

[Lee H]

Dip sticks and upper tubes are a matched length. In order to get the oil level right (assuming a stock pan) the tube and stick need to be a set. Either the short or long tube with the correct stick will do the job. The correct tube length for a 72 SB 2WD is a curved tube, 9 inches long from the block boss to the top with about 3/4 of an inch that goes into the block with an interference fit. The correct length dip stick for the 9" tube is 21 3/4. There are many sources for quality parts, Chevy dealer, although I'm finding these guys are too lazy to look for correct older parts and get annoyed when asked. Classic industries also sells real GM sticks and tubes. Stay away from the cheap chrome off shore products. GM Licensed products seem to be good quality.

For the GM # 3876870 upper tube, the correct dip stick is GM # 3951576 and the correct lower tube is GM # 3951600, all still available from GM for about $45.

The lower tube slips in before the upper tube. All GM motors came from the factory with a lower tube. The lower tube keeps the dip stick positioned in place to keep from getting hit by the crank shaft counter weights.

[big mike71]

I have one you can have if you pay shipping. I put on headers so the old one wouldn't fit. I bought a loker for like $80.00.