348 engine 409 intake-MDS dist misfit question

J

july2849

Well Known Member
I have a 348 block using a 409 intake-eddy 409 heads, every thing fits up fine. Went to drop in a MDS 8393 dist and noticed it does not engage the oil pump drive shaft.
Intake is a GM 3814881. I measured the block face to top intake @ dist against a 348 block I have sitting around and they are very close.

The 348 block w/ 409 heads I am trying to drop the Dist in measures 7 3/8" to he top of the Oil shat from the manifold, 8" to the btm of the slot on the pump. The 348 Block I have laying around measures 6 5/8" to the top of the pump and 7 1/4" to the btm of the slot and the distributer fits no problem. The MDS distributer is 7 1/8" long from the gasket to the btm of the shaft, means its not engaging the pump drive by 1/2"-7/8".

Obviously the is a oil pump shaft problem. Block is in the car, 59 El Camino and I can't drop the pan w/o pulling the motor. Any Ideas? Wondering if MDS makes a longer fitting. The dist meshes with the camshaft just fine.
 
J

july2849

Well Known Member
I'm sure thats true. The MSD Distributer is advertised as 348/409 and I assumed it would fit both. Something is a miss here, maybe there is an oil pump shaft difference in length. My slave block is an "X" truck block the other is a Passenger car. Both pumps were original to the blocks-to the best of my knowledge, and I don't have a original 348 Dist to check it against, darn it.
 
J

july2849

Well Known Member
Was going to ask MSD is they have a longer coupler. Is there any chance of installing a new longer shaft from the top side and getting it to couple properly. I've had the engine out enough times to have installed a zipper.
 
D

Don Jacks

Well Seasoned Member
Supporting Member 3
No,the pan has to come off,and the oil pump removed in order for the oil pump drive shaft to be replaced.Show Cars has the one that you'll need.A lot of this stems from the fact that some of the oil pumps are shipped with a new shaft,but it is for a small block.With the exception of the 64-67 Chevy II's[front sump oil pans],the oil pumps for the W and small blocks are the same.
 
J

july2849

Well Known Member
Question arises that why can't I simply make an 1/2" longer slotted sleeve that fits the MSD shaft on a lathe. The steel sleeve is currently roll pinned to the aluminum shaft-drive out the pin remove the sleeve. Sleeve looks hardened, I'd have to weld in a piece to fit the slot, then set a roll pin into the shaft.
Would beat pulling the motor again,
 
64ss409

64ss409

Well Known Member
Supporting Member 9
Some aftermarket companies such as melling, arp, etc make a pump drive shaft with a metal sleeve on the pump end. IF it is one of those in your W, you may be able to lift it out with a good magnet. That won't work if yours has the plastic sleeve.
 
J

july2849

Well Known Member
I have a 348 spare motor-not rebuilt, got some long needle nose pliers and the shaft popped right out less the nylon bushing. Pulled the pump off the block to see what happened and it appears to have enough room to get both the shaft and bushing out, but the bushing stayed on the pump, and doesn't want to come loose but the shaft slips right back in like La Hot Rods said.
 
J

july2849

Well Known Member
didn't come out has the metal collar-thanks for the feedback ordered new shaft and pump will pull the engine and drop the pan.
Thanks wrist pin, parts probably will be here by fri or Sat-Like to just lift it, drop the pan and pull the pump and shaft.
drop me a text.
 
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