It has been rebuilt stock, no porting. I have done it as a spare, my engine (touch wood) is still spot on & just done 60K. I did it for the experience whilst the parts are still available, the End Float is now done & is well within tolerance. I took my time & enjoyed doing it, now used up all the 'O' rings.
I think the important part is laying out all the parts first so you do not miss a any, having a good DVD/You Tube/Haynes as they all differ slightly & are mainly for 13B.
I think in the future if & when the engine is needed it will go into a Stock 7 as any need for more power will be satisfied by a 13B. Who knows if the FC vert does not materialise (owner still reluctant to part with it) I may find a needy FB to restore
I would love a RX4.