Motor mount question

So, long story short, I bought a 88 S10 Blazer back in 2007. I had a 305 in it and I just drove it around as a daily driver till last year when it died. I am upgrading the motor to a 355 with Comp Roller and Jegs Bandit Injection. when I took the old block clamshell mounts off the old motor I realized two things. One, the drivers side bonding had released so I need a new motor mount, which is ok because they are old and tired (drivers more so than the passenger) so I need to buy 2.
Now for the problem, I have had other cars in the past and they had the standard spacing on the clamshell tabs but the tabs on my block mount clamshell are wider i mesure 3.25inches between the bolt tabs (interior dimension). I am hoping someone out there might know what Chevrolet SBC came with this clamshell dimension a simple picture is attached as illustration of the dimension area. Please someone, save my ass. if this doesn't work I have to refabricate and I am retired and on a fixed income. I spent my extra money on a bottle of Jack Daniels to celebrate (just kidding) the day I fire this bad boy back up, Anyone know of a Chevrolet small block motor mount that had that spacing on the motor motor mount to frame tabs?