6.768

[TrackPack]

Anyone know why manufacturers of aftermarket big block replacement connecting rods make them 6.760 ceneter to center rather than the stock 6.768?

 

[snakeoil24]

Because that is the true blue print range number

 

[wyrmrider]

just put in new bushings and bore to your length on a tobin arp
rebuilding stock trds makes them shorter for starts
do not use any cores with the caps angle cut
what are you up to?

 

[TrackPack]

I'd like to gain some center to center length....as much as possible. It's going to take .005 to get the deck squared, but I don't want to take an additional .008 to make up for shorter rods.

 

[wyrmrider]

not a problem
do the big ends to see how much shorter it makes the rods and go from there
pick bushings with enough beef in them to offset bore or make your own bushings out of bar stock

 

[dvw]

If all the available rods are .008" shorter why are you worried about cutting the deck .013" vs .005" if it's getting cut anyway? Then if you need a rod later you're out of luck instead of just buying a replacement. Not to mention the expense of rebushing and remachining the rods to make them longer.
Doug

 

[TrackPack]

The deck would need to be cut .033 to get to where I want to go with 6.760's

How much can the deck be cut before creating problems?

 

[dvw]

6.768"-6.760"=.008"+.005" to square the deck= .013", correct? So you need .033" to get the deck height you desire vs .025" with stock rod length, correct? Whats the big deal?
Doug

 

[TrackPack]

Yes, that is correct.

How much can the deck be cut before you start having problems with block integrity, intake manifold fit, etc.?

 

[dvw]

Depends on the stack up, intake gasket thickness, head gasket thickness. Mock up the heads and intake on the block now. Simulate heavy milling with no head gaskets and see if the intake will fit with gaskets.
Doug

 

[TrackPack]

Thanks, you just reminded me...... I was going to use a .039 head gasket, which will make up much of the difference. Should have very little mismatch with intake manifold, port height, china wall, with the amount I'll have it decked.

Much appreciated.