Ok anybody know whats up with my oil cap? I havent been able to find a valve cover oil cap yet that will fir off the shelf localy.

Aparently in my 88 T/A its a swapped 350 TBI out of a caprice.
Now ive lost the oil cap and need a new one. The problem? The valve cover hole is at least 1 1/2". The bigest cap ive found thus far is 1 1/4. They all just about fall in. Right now i have a rubber autozone cap/plug that barely fits.

The hole is also quite deep. Anybody know whats up with these valve covers? Was there some special version of the caprice 350 (police issue maybe? Dunno) that used an odd size cap for whatever reasons?

Hell, Summit doesnt list any oil cap over the size of 1 1/4" for Camaros/Firebirds.

PLEASE any clues would be nice. More so than needing a cap im really interested in knowing why its such an odd-ball size, history etc.

As always, any help is apreciated.

 

well if it was me, id pop the valve cover off and take it to a scrap yard and look for caprices and try to find a cap that fits, you could even try chevy & gmc trucks.

 

I guessing that your valve covers are centerbolt style. The later ones used a threaded 1 1/4" hole.

The earlier ones used this style of filler cap that twists onto a lip like a radiator cap.

 

I actually think that looks right. At least it would explain the depth of the hole and the lip on the inside.

What do you mean by centerbolt style? The positioning for the bolts themselves? They look and sit just like this

Odd how these on summits page have a standard 1 1/4" hole and mine is 1 1/2. But besides that theyre exactly the same.

Thats off an earlier one? As in how early? I was led to believe the 350 was out of an 88 caprice. (and was told it has 64K miles on the motor...it sure runs like it has that or less, dunno if its original or not though.)

 

An '88 caprice would have an oil cap like the one I posted.

Edit because of your edit:
Center-bolt as opposed to perimeter bolt.

The later valve covers you posted have a threaded hole and take a plastic oil filler cap that looks like this.

 

I wonder if it had an extension tube, get the cap up over the big body car's accessories. The actual oil cap would go on the tube?

 

Just buy some new valve covers

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