ARP Main Studs & Bolts Detailed

Well I contacted ARP and a few other companies that sell their bolts & studs and some that even make main caps for Small blocks, B, RB & Hemi engines. And I spoke with a few guys and shops in the past few days that build some very serious power. I was trying to get some sort of common ground IE opinion on the stud issues and concerns, and the problem with the #5 main cap and oil pump interference when using the ARP studs.

Bottom line, they all list one kit for A, B & RB mopar engines. They folks at ARP agreed that there should be a kit or 2 just for A blocks with studs, with and without a windage tray support and 6 point and 12 point head combos. Also I found some folks enven using the bolt only ARP kits are leaving the washers out. If ARP and others had as many options in terms of kits offered as the GM & Ford guys we would have no issues! I doubt that they will offer the kits w need. Sucks! Typical everybody seems to hate mopar and brush them aside attitude! I know I worked for 15 years at GM but always drive a Dodge! We get one starter water pump fits all they have 20+.

Some people use a bolt with studs, some leave out washers and all sorts of other ways to get around it. Not the best solution but will work. Why waste the money and have a weak link, do it the correct way I say. Got great feed back here on the site from many of you guys who have been there done that. Greatly appreciated guys!

Anyway, I have all the part numbers listed here and the required options we have to us. Also note, if you measure the stud in your engine and it depends on your brand and type of oil pump, HV or standard, you can get an ARP stud that will fit and with the washer and a 12 point hex nut. The 12 point hex nuts are smaller and give more room. You should be able to clear the pump without grinding it down or milling the cap.


:coffee2: My take is this: A big block stock puts out 500 ft lbs torque, I have built them for years with 600+ hp and 550+ ft lbs torque, never had a failure. Maybe I am lucky? But the same bolts are used in a small block. I have had a 273 spin over 8500 rpms for years never failed. Built 3 340-6 pack engines that dynoed 405 to 445 HP at the crank. Granted it makes way less torque than these 416 strokers. That being said it is probably a good idea, safetey measure in a stroker anything inch size to do studs or at least better bolts on the mains & rods or just better rods withthe bolts. In the old days I guess we just winged it, I have seen a lot of broken cranks, never a cap or a bolt failure except on blower and turbo motors and Nitro and fuel motors. Most times it is a crank or rod that blows. But now we have better options these days. So why not go for it?

Here are the results of days of questions and results with part numbers.

ARP Standard main bearing bolt kits for all A, B, & RB engines except HEMI's and some late model magnums
180 PSI bolt kit 140-5001
Part number of the bolts included in this kit if ordered seperate each are
part # HAR3.250-5

Stud kits all rated at 190K psi
140-5401 6 PT $81.96
140-5402 12 PT $77.32
140-5501 6 PT $86.96 with tray support

Note all kits use 190k PSI strength studs, and ARP makes a special bolt of the same stud strength. You will require 2 bolts of the 190k PSI kit for oil pump clearance and even load on the #5 main cap. These are low profile headed 12 point in design bolts that are the same strength as the studs.

Special low profile 190K psi bolts
Bolt Part # 6AR3.250-1L
per bolt from ARP $5.70 each without washer
WASHER part # 200-8513 $1.00 per washer

Torque values WITH LIGHT ARP MOLY LUBE
85 STD 180K PSI BOLT
95 HD 190K PSI BOLT special low profile bolt
90 STUD KITS 6 OR 12 POINT

180k psi bolts used as replacements from stock most likely will be Ok on line hone, but need to check clearances

190k psi bolts & or studs used as replacements from stock most likely will NOT be Ok and will required line hone of block from a decent shop, but you need to check clearances 1st after torqued to specs. And when you get it back! I have seen a lot of bad line hone jobs too.