I have now bought (yesterday) a set of con rods. I have had them posted down to the engine builder in Bridgewater, Somerset. I spoke to him about bolts - and he confirmed that the original ones were no longer available.
I then started talking to him about new ARP's and drilling and tapping etc. His response was, "well, firstly why don't you see if you can re-use the existing bolts?"
That stopped me in my tracks for a minute......
I said "can you.....?"
He said that once he had the rods he would inspect, check and test the bolts and see if they could be reused. Clearly I was initially dubious, but then I have to remember this is a person who is the owner and grandson of a business who has done nothing but engine machining and building for roughly 100 years! He gave me that look of - well you can retap and fit new bolts, but with some checking and testing done - do you really have a specific need to? All, I could reply with was 'errr.... isn't that established practice and it is what everyone does - don't they??"
He asked some questions regarding the (my) specific application, I said I was not intending revving above 7200 - 7500. He then asked if I had ever heard of a 33 16v 33 big end bolt letting go. Well having had roughly 20 Alfa 33 and following the Alfa race series over the years I had to think about that one and confess I hadn't.
He said, "let me get the con rods and bolts on the table....." and that he would come back to me.....
Any thoughts on that little lot.....?