Main bolt conundrum help needed...

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J

j par

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So I'm taking the 77 car 360 block that I have in the back of my shed down tomorrow for preparation machine work. I have a 71 360 that came out of the truck and ran just great. I have videos of the kid doing cookies out in the field and it sounds awesome. I've robbed the truck oil pan off of it and a couple other small goodies but I don't want to take it apart because it is a good running engine that just needs tin....
So I go to rob the windage tray off and I'm going to one by one on torque and torque down the number two and number four main bolts.. I go to take the main bolts out of the what I believe to be a factory untouched 77 block and the bolts are a little mismatched. I go to take the four main bolts out of the 71 block and they're all exactly the same and have a different insignia on the head of the bolt.
First question is there something better or worse here? My first inclination is to one by one on torque and torque in the bolts off of the old 77 360 and take the nice matching set of bolts off the 71 block because it is up for sale anyways. I don't think I would be hurting anything if I just took one bolt out at a time and retort it down in?
anybody and everybody's experience and thought on this would be appreciated thank you..
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That's the 71 with a couple of the main bolts from the 77 to compare and this is the 77..
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I don't remember a double stack of washers under the windage tray bolts I thought the extended bolt took care of that?..
The other thing besides the 71 being probably a great running motor as it is it feels and it seems like it's hard to get my calipers around the Piston but it may be already 30 over.. we know this didn't come with the 596 heads that are on it...
Or at least I don't think they made those then?..
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For mains 1-4, there is no seal to disturb anyways, so it's perfectly acceptable to completely remove those main caps for inspection, then re-install them and re-torque it. I am curious to see if it has standard bearings under those caps.
I never seen a factory original block with washers under the main bolts, so I am guessing it is not original.
 
Bobzilla said:
For mains 1-4, there is no seal to disturb anyways, so it's perfectly acceptable to completely remove those main caps for inspection, then re-install them and re-torque it. I am curious to see if it has standard bearings under those caps.
I never seen a factory original block with washers under the main bolts, so I am guessing it is not original.
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Yes that 71 block I really feel has been messed with. I can't wrap my head around a 71 with smog heads but it could I guess. What's weird is the 77 block is the one with all the miss match stuff and it's the one with Factory bore size and didn't seem messed with when I took it apart...
 
MoparLeo said:
Just pull a main and rod cap and look under the bearings to see if it is over/under sized. The piston top should also be stamped what oversize it is.
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The 71 that is together really doesn't matter if it's oversized or undersized or bored. I'm going to sell that one anyways as a runner. The less I take apart the better. Again I was just going after the windage tray for my build when I noticed that the engine I was going to keep had two different kinds of bolts and the engine that I was going to sell had one kind of bolts that were even different again. But they are 6 years apart...
Also I noticed with the 1971 in the serial numbers it didn't have 360 dash something like the 77 had 360-8...
 
If there was any question in my mind, I would buy a new set of ARP bolts and install them. Those bolts are nearly 50 years old. It would also give you the opportunity to inspect and maybe plastigage your main bearings at the same time. JMHO.
 
Like RustyRatRod said, it’s just different markings from different vendors. If you are not going to push the limits of that 77 block, don’t worry about different markings on the bolts. If making big power, just get a new set of bolts and be done with it, so it’s not in the back of your mind later on.
 
Bobzilla said:
Like RustyRatRod said, it’s just different markings from different vendors. If you are not going to push the limits of that 77 block, don’t worry about different markings on the bolts. If making big power, just get a new set of bolts and be done with it, so it’s not in the back of your mind later on.
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Yes I think what I'm going to do is just resolve myself to switching out the bolts and having the nicer more uniform set for my 77 block. I'm going to build a stroker for my 74 Power Wagon but it's never going to see above 5000 or 5500 anyways and it's going to be more of a daily driver with low torque...
I've got stock bolts in my Stroker motor that I built for bracket racing in my duster and it's been fine for 5 years. I just thought it kind of odd that there was three different kinds of bolts LOL I prefer one and just call that my peace of mind..
 
oldkimmer said:
The washers come in a windage tray kit. 273/318 main saddles are shorter than 340/360 caps. Kim
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That explains things a lot! Thank you..
So get rid of the washers because it's on a 360..
I guess the next question is if I build a stroker will I have to have spacers for the windage tray?..
 
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