building a 500 stroker and didn't know if a girdle would be to my benifit? won't turn it over 6500 i doubt,hopefully close to 600 hp? just any thoughts? thanks moparts

Better main caps maybe, but a girdle isn't needed at that hp level. I have run stock rb blocks with some pretty heavy rotating assembly's over 600 hp and had the stock caps, didn't break any. If it is going to be a 400 block, no. If you plan to up the hp down the road with either, then I would use either Aluminum caps or some better steel ones.

i would. cheap insurance. my caps walked at that power level. no more with a girdle. do it.

new aluminum main caps are about $350. a girdle is another $450.00 and comes with all the hardware and main studs from us. it is cheap insurance to get the girdle as you won't have to switch caps or remachine the block and shim the girdle at a later date if you decide to add a supercharger, turbo or nitrous. also street miles tend to be particularly hard on an engine with alot of stop and go driving and possibly not optimized oil system. again its cheap insurance, and at that power level i would do it.

I have bought, installed and used after market main caps to increase the bottom end strength of the Mopar BB, both high and low decks. The RB and earlier B motors(361and 383) have thinner main webbibg than the 400 block due, I have seen several RB with cracked main webs Main caps or a girdle will not stop that, it is usually caused by detonation or over revving or both Stop and think about the design of the Mopar B, RB and 426 Hemi, part of the main webs are above the upper main bearing between the bottom of the cylinders and them, part of the webbing extends down below the cylinders and the main bearing bulkheads and part of its strength is the skirt of the block that the oil pan attaches to also Pretty strong in my opinion Using the oil pan bolts and main bolt studs in a girdle will probally limit the motion of the girdle forwards and backwards, it may limit how the main cap wiggles around some, but it will not make a standard block any stronger than its weakest point is My pump gas 518 C.I. 400 block has all five main caps replaced with the Mopar brand ductile iron main caps and ARP main studs. I originally ran that motor with a 4.25 stroke crank with 9.25 to 1 compressio ratio, ported big valve 906 iron heads and a six pak intake and carbs, I dyno tested it(34 pulls with a lot of tuning changes, 612 HP at 5600 RPM,644 Ft. Lbs torque at 4500 RPM on CA pump gas)) and ran it a small amount on the street here locally and raced it some the first year I got the car running.It ran 10.69 at 124,5 MPH weighing 3425 lbs with me in it on Oregon pump gas through the mufflers and with the air cleaner on I switch the heads that winter to a set of Eddy RPM (same exact CC as the 906 had )that I had CNC ported by Jeff at MCH, that change pick the car up to 10.49 ET and 128.4 MPH I did look at the bottom end and saw some main cap walk and metal transfer , I filed them smooth and put the motor back together. The next winter I decide to remove the motor from the car again and change the crankshaft from the 4.25 stroke to a 4.300 stroke to raise the pistons up from -.025 to zero deck to increase the compression from 9.25 to 1 to 10.28 to 1. During that tear down I notice some more cap walk and metal transfer from the caps to the block, not as much this time as before I filed the caps and block smooth with a fine mill file and put it back together. I had found that the motor liked to be shifted at or above 7300 RPM I also forgot to mention that when I built the motor I used a set of low tension oil rings I ended up having the block rehoned on the second tear down and put in a set of standard tension oil rings The next time I looked at the main caps and block no more cap walk or metal transfer The last time that motor was on adyno, I had switched the heads to a set of Indy M.W. port SR with a single 1050 Dominator intake and carb. and freshen it. It made 727 HP at 7000 RPM and 710 Ft. lbs at 5600 RPM, that was two years ago and everything looked really good on the bottom end that year My message is to go for the after market main caps and main studs if you want to use a stock block Save the money on the girdle and buy a better block next time

my biggest regret is not going to aluminum main caps when I first built my 493 which I did on it's first freshen up but spent money twice basically, not much but still did. I don't run a girdle

I did not on my 493. I went with new billet steel main caps and ARP studs. But its a street car I only race a few times a year at the most. Been holding up fine as I guess it makes about 600 hp to push my 3700 lb 63 to 10.70's so far. Ron