Main Bearing Clearance

[78Bu88SS]

I'm putting a little 350 together and just measured up all the main bearing clearances. I used a mic and dial bore gauge, and confirmed the measurements with plastigage. I'm getting .0020-.0022 on #1, 2, and 3. #4 has .0018 and #5 has .0032. I feel comfortable with 1, 2, 3, 5 but I'm wondering if #4 is a little tight. This is basically a stock bottom end that will probably not see over 6000.

 

[bowtie81]

tighten everything down to specs and spin the crank feel if it drags in any spots or if it spins nice and free. if it spins nice and free id say your alright

 

[Doober]

I'm not sure what the specs are on the older blocks, but the one-piece RMS blocks say something like .003-.0035" is actually the service limit. Mine were close to this, but the main reason I changed my main bearings was because mine were full of crud and just looked really crappy in general. You'll be fine, those clearances are close to what mine had. Just make sure to get a good oil pump.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SLP-224-4146A&N=700+4294925232+4294839075+4294863521+400220+4294908216+4294755178+4294908395+4294925005+4294840140+115&autoview=sku

A little more than you'd pay at Autozone, but it's the thicker casting. Look here:
http://maliburacing.com/forum/viewtopic.php?f=4&t=35654

 

[78Bu88SS]

I seated the thrust bearing and everything is torqued. Spins nicely with no tight spots.

I measured all the rod bearings and using a mix of .001 and standard halves have all my clearances at .0022-.0026.

Overall it should be a tight little motor. I have a M55HV before they cut down on the casting size, along with a oil pump driveshaft with steel a collar.

 

[Doober]

How are you securing the pickup tube? I got a nifty little clamp from Jegs that bolts to the pump body and wraps around the tube to keep it from coming out (as opposed to welding).

 

[78Bu88SS]

How are you securing the pickup tube? I got a nifty little clamp from Jegs that bolts to the pump body and wraps around the tube to keep it from coming out (as opposed to welding).

Got the same actually, on more then a few motors.