4 bolt mains

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SWED67barracuda

SWED67barracuda

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Hi , Has anybody on this forum ever used Milodon 4Bolt maincaps #MIL-11300.I`m buildin a 0,040 over 340 with W2 heads and thinks these look OK.But experienses are always fine to know about . Best regards Ubbe.
 
what I understand is 4 bolt main caps will weaken a stock block because it will need to be drilled in the main webbing that will cause a weak point . good ARP studs and a 2 bolt billet main cap is the best bet some mill the outside hole off the caps you speak of and use as a 2 bolt main with ARP studs also .
 
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I used em on mine. Have not had any problems, but looking at it there is not much meat on the block where the extra hole is tapped. Would not do it again.
 
QKFSH67 said:
I used em on mine. Have not had any problems, but looking at it there is not much meat on the block where the extra hole is tapped. Would not do it again.
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They say it pulls from the sidewalls of the block and not the flimsey main web area , but do the outer bolts really reach that far out. I have seen some kind of girdle that bolts on the main caps, could that be something to use?
 
if you think 2 bolt billet caps and good studs will not handle your power level it may be time to look at a better block . what I understand is a girdle does not do much for a sbm .
 
Would not use girdle. Honestly many w2 headed 2bolt main small blocks were raced in 70's and 80's...biggest problem was keeping oil to the rod and main bearings.
 
QKFSH67 said:
Would not use girdle. Honestly many w2 headed 2bolt main small blocks were raced in 70's and 80's...biggest problem was keeping oil to the rod and main bearings.
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Ok Thanks for input . Saves a bunch of money , I`ll buy ARP studs instead.
 
I have 2 blocks here, 1 has Pro Gram caps and another has what I assumed were Milidon caps. I don't think I would do it, unless nessasary. I think I like the Pro Grams better

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This block was fitted with program caps by ray Barton years ago.
 
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SWED67barracuda said:
Thanks , very helpful picture , So the outer bolts are somewhat offset to the centerline . I think i must do some measurements on my block , just because , even if I`ll go along with what QKFSH67 says about the matter.
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Maybe no help here, but I had the splayed bolt caps installed in a really hot 406 sbc, the main caps still walked around , but like I said it was a high h.p. engine !
 
Don't waste your time with 4 bolt caps on a production block. It won't do anything except lighten your wallet.

If you need more than that, buy a better block. All the little tricks and gadgets like girdles and all that don't do squat.

Those blocks are inherently weak in the main webs. Putting another hole out there and then pulling on it just compounds the problems.

If you want to verify this, start bolting stuff on the block and watch it pull the main line out of round. Then you can finish the main line and get it nuts on. Untorque the caps and torque them again and watch them move. They will constantly move around.
 
I used some beefier iron aftermarket 4 bolt MP caps and cut the outer tabs off and used good studs. Seems to work well. Program and a couple of other aftermarket companies offered 2 bolt caps. I may still have correspondence with one of them I can forward if you are interested. Just PM me an email address.

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Rocket said:
I used some beefier iron aftermarket 4 bolt MP caps and cut the outer tabs off and used good studs. Seems to work well. Program and a couple of other aftermarket companies offered 2 bolt caps. I may still have correspondence with one of them I can forward if you are interested. Just PM me an email address.

View attachment 1715094486 View attachment 1715094487
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Hi there Rocket , That looks real nice .I Think you got my e-mail adress , I bought the heads from you. Please forward info. Best regards Ubbe.
 
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