No good Mitch, bolt pattern isn't Briggs even though they say it is. Shaft is only 7/8th and you need 1"for the pulley. Somewhere here Mitch I have all the bolt patterns drawn up and the fact they detail the bolt pattern is enough to tell me it isn't. I have been caught twice so very wary And I just checked the 7/8th shaft is for push mowers and the bolt pattern on these motors is nowhere near the push mower Briggs pattern. Not sure haven't checked but it might line up with the Honda GXV motors, not that any of this helps you
I’d go the genuine route if I were planning on doing real work with the thing. Those motors are very hit and miss. If you have a relationship with a B&S reseller or local mower shop have a chat and they’ll give you the lie of the land. Some repower units are on a six month backorder because of shortages created by the CoVid pandemic.
I needed a whole new high lift water pump and I ended up with a unit sitting in the shed in a much shorter time by dealing with someone I knew. I’ve heard of others waiting months longer.
Depending on the vintage of the colt 5 you may only need a 7/8 shaft. I have seen colt's with chonda engines on them. 4hp engines were also fitted to the colt mini and I know they did not have a 1" shaft. The only trouble you may find, depending on the engine, is starting it. As it will not have a blade on the bottom, only the pulley, many briggs engines will be very hard to start.
GXV160 Honda engines are a fairly nice fit but expensive, they work well as they have a heavy flywheel.
Nath, Hendersons Mowers in Ballarat have GXV160's for about $550 so they are pretty good pricewise, they have a 7/8th shaft. If you go to the GXV160 off the self propelled Hondas they have the 1" shaft but they are about $50 dearer. Firstly you need to get the pulley off to check shaft size and you can go from there
