NB engine in a 1990 NA?

[Colonial]

Opportunity has come up to purchase a rebuilt 1990 NA MX5, roll bar, suspension etc etc

It's had a NB 1800cc and gearbox conversion.

Is this a common swap? It's been well engineered by a reputed MX5 race car builder in Australia.

[GravelBen]

Should be fine, they're just like big meccano sets really