[ComradeNorgren]

So as i was Bolting on my new oil pump it suddenly felt like the bolt stripped out. I pulled the bolt off along with the pump and noticed that a piece of the casting on the main cap broke off. So do i just tap out the whole and pretend nothing happened? It still threads the bolt, or would i have to replace the entire cap? have any of you guys had this problem before? I've built about 4 350's and have never had this happen to me :/ Here are some pics to help you guys visualize it better.

[1986c10]

hahahah this is awesome. I did the exact same thing yesterday and about **** myself when i saw the casting broke. my problem was i used a 2pc rear main bolt on a 1 piece rear main cap. The 2pc bolt is shorter and started to get hard and pulled off the top layer of the casting because the bolt wasnt threaded enough. Lucky for me i have a spare block and cap that i just swapped in and got a longer grade 8 bolt. I personally wouldnt reuse the cap cause i bet more of the casting will flake off and get in the oil. And you cant weld cast iron so i think you should get a new cap.

[BOBCRMAN@aol.com]

Swapping a rear cap is invitation to disaster. Caps are bored to the specific block it is in. The chance of getting an identical cap is as good as finding an exact twin of yourself.

Best remedy is to get a stud and hand tighten it in the hole. Then install oil pump.

[ComradeNorgren]

when you say hand tighten the stud in the cap what do you mean? and how deep should the stud go in? i've heard you can run in to problems if you have a longer bolt than what it should be at.

[BOBCRMAN@aol.com]

If you finger tighten the stud. It will have maximim thread engagement and will not endanger the main bearing

[ComradeNorgren]

gotcha, so it won't loosen itself up?

[lmsport]

Some caps are drilled through to the back of the bearing, so verify that the stud is bottoming on the cap.

[1986c10]

sorry for the bad advice. looks like we have the same problem. Where can you get a stud and nut to fit. do regular hardware stores have them or do they sell a specific one for a job like this?

[ComradeNorgren]

Looks like ebay has them, thanks a lot guys, saved me a lot of heartache. haha

http://shop.ebay.com/i.html?_from=R4...All-Categories

[TroyBoy]

I agree with Bob. That was gonna be my advise. Get a good stud from ARP thru Jegs, Summit or Speedway. Buy a name brand part for this job.

[MouseFink]

The problem is solved by using a ARP stud. The threads of the ARP stud are not long enough to contact the bearing or bottom out in the hole. Another advantage in using a stud is that the threads in the cap are saved.

Use a ARP 230-7001 stud kit which includes a 6 pt. nut and hardened washer. Fits a SB Chevy with std. vol. pump. Screw the stud in by hand with a little Red Loc-Tite until it stops on the shank. Install the pump and torque the nut to 35 lb. with the threads lubed with a light coat of 20 wt. engine oil.

SB Chevy with a high volume pump...Use a ARP 230-7003 stud kit.

[1986c10]

I have a 1pc rear main seal and am using the melling select pump which is the same size as a hv i believe. Would the second arp stud kit work for me? because a standard m55 pump bolt was too short.

[MouseFink]

The ARP 230-7003 stud kit is the one to use with a HV oil pump. My 1991 4.3L V6 engine has a 1-piece seal, a Melling Select 10552 HV/standard pressure oil pump and I used a ARP 230-7003 stud. That stud is for a standard BB Chevy pump and SB Chevy HV pump.

I have not compared the two studs but I assume the difference is in the overall length. The overall length of the ARP 230-7003 stud is 3.125". The Melling Select pumps have a heavy duty neck for use with solid motor mounts. I used a Melling Select 10552 HV pump because of the remote oil filter/ oil cooler plumbing in my S-10 Blazer 4x4. It has a longer oil pick up tube/screen assembly and is subject to more vibration in the stock 9-1/4" deep oil pan. I also added a pick-up tube brace to the 3/4" tube assembly. (Don't use the Melling bolt on pick up tube - it can break at the pump - bad design) GM recommends a 21 lb. remote oil filter adapter oil by-pass with oil cooler and remote oil filters instead of the standard 11 lb. oil by-pass. The HV pump would by-pass too much oil with the standard 11 lb. oil by-pass. The Melling HV pump will create a little more pressure than a standard pressure pump even though Melling claims it doesn't.

The bolt for a stock oil pump and a 1-piece rear seal is 2-3/8" underhead length. The stock bolt for a 2-piece rear seal has 2" underhead length. You can see where that would present a problem if you used the wrong bolt.

[MouseFink]

You should use a GM 10456413 case hardened distibutor gear with a HV oil pump. That gear fits a stock .491" OD distributor shaft. If you have an aftermarket distributor (MSD pro-billet, etc.) with a .500" distibutor shaft, use a MSD 8531 case hardened marine certified distributor gear. The high volume pumps will prematurily wear out a standard distributor gear, especially if it is a used gear with a existing wear pattern. The HV oil pump are more difficult to turn and puts more pressure on the distributor gear. That is not so with a "high-pressure" pump. A high pressure pump is a merely standard volume pump with a oil by-pass that opens at a higher pressure. The higher oil pressure does not put more effort and wear on the gear.

[1986c10]

Thanks mousefink. Great info, just ordered the parts!