Holding back are higher rpms

[Steptoe]

I had this issue of holding back around the 3500 rpms a few yrs ago, and chassed my tail trying to find why
The usual stuff ..restrictions in the lines, shut off valve etc....turned out to be the VFF vac shut off valve wordnpin and housing...replaced the unit.

Has been doing it again....So I pulled the pin out, blocked the vac line by replacing the tap with a screw in blank...not that.
But when I was putting the 1" hose back on the convertor, I noticed the inner layer had been attacked....yes this is a reinforced, oil HC resistant pressure hose...used for mini fuel tankers...this stuff is not cheap.
The inner layer has swelled at the lower end only, enough to block approx 1/3 of the diam, split and formed a flap, that then restricted a lot more of the line.

I have done a lot of mileage on this dedicated system in the last 15 off yrs... other things are getting worn...in partular the holley base plate throttle bushes....it is now at the piont the sec butterflys are closed up just touching the bores.
Im having a problem locating another base plate only in NZ...so Im thinking of re bushing.
One can buy re bushing kits from Summit with the reamer included...by the time one takes into a/c exchange rates, shiping, local sales tax (GST) one can damn near buy a whole new carb.

Does anyone know the size of the bushes and the size of the reamer in these kits?