I am in the process of assembling my lower end and could use some help here. The gasket set I bought came with a 2 piece rope rear main seal so I ordered the bs6141 fel pro 292 Ford seal to replace it today. I just want to make sure the procederes I am doing are correct. I was told that when I put the rear main seal in I should just lube it and not use any rtv on it. Is this correct? I also read somewhere that when I install the main cap I should stagger the ends of the seal? I ordered some plastiguage today to check clearances. It has been a long time since I have done this so I am questioning my memory here. I would put the plastiguage between the main bearings and crank shaft, then torque the mains down to crush the guage, then loosen main cap and check plastiguage against the chart for thickness. Then repeat for rod bearings. Is this correct? Do I need to check both halves of the bearings? This is a 68-72 350. Anyone know what the stock clearances should be? Any and all input is greatly appreciated.

 

Your procedure for the Plasti-gauge is correct, I stagger the seal ends and use a VERY small amount of RTV on the ends of the seal. Make sure you put a little engine oil on the threads and torque to spec. Factory main specs are .0005-.0021, which IMO is too tight. The old rule of thumb ".001 for every inch of journal" is a pretty good one, IMO. On 2.5" mains you are looking for .0025 +/- on mains 1-4 and .0035 on main #5, +/- Factory calls for .0004 (which IMO is too tight) - .0033 (which IMO is too loose) on the rods. Again, .0020-.0022 is good on 2.125 bore rods. We do run them a tad tighter (.0015-.0018) when using coated bearings. The above statements are my personal opinions, certainly not Gospel.

 

I'll concur on this. This is the procedure I always use.

 

Thank you for the info and I am glad to see I can remember. It's probably been 6 years since I've seen the inside of a motor. Tis is my first Olds motor though. Any suggestions on measuring crankshaft end play?

 

Pretty hard to do without a dial indicator. But then, you will need it to degree the cam anyway, so you might as well buy one.