Finishing Up a 350 Reuild
 

I'm almost done with my first-ever engine rebuild & yes it's very exciting. However I cant seem to find info on the tiny finishing touches. For instance, what do I do with all these extra holes in the block?
There should be a plug for the cyl head that doesn't have the temp sender in it, but there's also:
One fine-thread hole at the edge of the intake, under and behind the distributor
And 2 very small holes above the bell housing
I wouldn't be surprised if there are a couple more I haven't noticed.

Thanks in advance!

Re: Finishing Up a 350 Reuild
 

If you are refering to the threaded hole in the block behind the distributor
(1/8 -27 thread)--that is for your oil pressure sensor or oil pressure line to gauge. Don't start your engine with this hole open....you will have a HUGE oil leak !

Re: Finishing Up a 350 Reuild
 

Are you referring to these two small holes above bell housing ? (1st pic)

Second picture is where your oil pressure sensor goes, it is actually a 1/4" hole for a sending unit if your running an oil light or use a 1/4" -1/8" reducer if you are running a pressure guage. Like the one I have pictured. Hope this helps. :chevy:

Re: Finishing Up a 350 Reuild
 

72bowtie & GR8-68, thanks for the quick responses!

Oil pressure sender- now that's slightly important, but I never thought about it, or saw it mentioned anywhere in the rebuild manuals I've got. Looking that up, I see that I've got yet another hole to fill: the alternate mounting above the oil filter.
GR8-68, is that a tube coming from yours? Where is the actual sender mounted? The photos I'm seeing show it right on the engine block, often with an angled fitting.
Yes, those are the 2 bellhousing holes I meant. What are they for?

~W

Re: Finishing Up a 350 Reuild
 

The hose is actually the oil line to the gauge, some previous owner put a rubber hose over it to protect it. The two holes I have no idea what they are for but they are on all the blocks but do not go all the way through. Something to do with the casting maybe.

Re: Finishing Up a 350 Reuild
 

That line is for a mechanical guage

Re: Finishing Up a 350 Reuild
 

If you have a light rather than a gauge you would use this

Re: Finishing Up a 350 Reuild
 

In post #3 with the 2 holes close together, these were used to index and hold spark plug wire holder looms. One hole threaded to hold down the bracket and the other hole was used for the loom indexing notch to fall into to prevent it from moving around. The plug wires run behind each cylinder head and then under the exhaust manifold to then come up and "Y" off to each pair of plugs. The wires ran along side the block down low to stay under the hot exhaust manifolds and near the block to be retained with more loom holders.

Re: Finishing Up a 350 Reuild
 

Nice, thanks for that info. Now that you say that it comes back to mind, back in the day I remember taking some of those off :chevy:

Re: Finishing Up a 350 Reuild
 

Good pictures....The tapped hole in the block for the oil pressure sensor IS
1/8-27 tapered pipe thread though, not a 1/4" hole.
1/8-27 thread mics up as .390 O.D. 1/4" is .250 O.D.
Trust Me ..I have 40+ yrs. of experience as a machinist.

Re: Finishing Up a 350 Reuild
 

Sorry, you are correct, these can sometimes be confusing