I haven't quite got the carbs in yet (still rebuilding them) but planning to fit them. Have trial fitted them and all seems okay - though no room for air filters without some 'modification'(read angle grinder).
There are two types of rootes 1725 alloy headed engines - fitted to vehicles before 1967(ish) think rapiers/sceptres/alpine/superminxes etc. These were mounted vertically, had course splines on the gearbox / prop, and had the smaller earlier type OD units - and in my opinion should be pretty much a straght swap into a commer.
After 1967 (ish though there is some overlap) the 'Hunter' range of cars came out (inc the H120 and Hunter GLS Holbay modded ones). In these cars the engines are canted over slightly (20degs?), can't remember why - but when trying to retro fit one of these engines into am earlier vehicle - a commer, the engine needs to made 'vertical'. This is simple to do as you just take the front plate off you commer engine and put it on the donor hunter motor. easy job.
The problem comes if you want to use the 'hunter' gearbox, this has the later (bigger) OD and more splines on the gearbox and prop. If the engine has been made 'vertical' the gearbox will now be canted over. There seems to be just enough play in the commer linkage to accomodate this (wait out!).
A more cunning idea might be to use an earlier OD gearbox (pre hunter and course spined). Word on the street is that a GT6/Vitesse cluch plate can help marry things up here, or just fit the flywheel from you commer.
If you don't like twin strombies, there are single carb variants, twin zeniths, twin webers...
Exhaust was straight forward. used bits from
http://www.jetex.co.uk/website/custom_parts.php?mat=Aluminised+or+mild&dia=1.75+inch
Prop shaft i just cut and shut the rapier one with the commer one. will probably get it balanced by someone like
http://www.propshaft-services.co.uk/ This isn't expensive, will get them to fit new UJs at the same time.
Crossmember I haven't done yet, but will be straightforward.
Gearlinkage is proving a little tedious, bent and rotated the support bracket to get some distance and unscrewed the rear part of teh linkage to get a couple of inchs. Seems okay - but gear knob now very close to dash. Think this will require further love.
