I purchased a fresh 454 block that had 4 bolt caps added and aline bored ( caps attached with factory bolts). I wanted to add main studs to attach the caps and a local machine shop told me if i did the 454 would have to be aline bored again ! Now i have added studs to many bbc unbored and fresh aline bored, after machine work is done and i have never had a problem ! So has anybody else heard this ?? Thanks tom

 

Hello:

I concur with them. Once they mount the studs they must be torqued into the block and this may cause some distortion that affects the alignment of the passages for the crankshaft journals. It is from the fact you are installing studs. It can't be that expensive to do that second line bore and it is peace of mind. Are you going to do all that work assembling it just to find out they were right maybe 20,000 miles later? I would get the second line bore. If you don't want it then use bolts.