go the 1600 square B&S the 132 diffs are borgwarna and rated to like 500hp and gear boxes are pretty tuff they just have small fluid containment so you'll need to check it like every 1-2weeks you can put like a lil swirl pot type insert in it for a bit of insurance i had 124cc with 1.8ltr with twin webbers it was awesome good luck

The engine and box were sold to another fiat nut in canberra. It was the same as the fiat 125 engine but had the reversed transmission/box assembly to fit the 850 body.
I hillclimbed it once and kept hittting the kerb with the rear wheel cause it stuck out so much.

I doubt there would be any left these days as they were so bad for rust. Still a beautiful car to drive though

Sounds like youve had it all Feral! It would have been a site if you still had your beard then and stepping out of that thing with all the race gear on like a bikkie forced to drive someone elses mad contraption!
Spud Thanxs for the advice bout the box I didnt know.. The diffs are heaveeey so Ill stay away from them but Ive got an Alfa finned alloy cased lsd with finned sump thall come handy when it goes in.
Bout the engine I was thinking of the 1585 and 1756cc with 84mm bore not the earlier 124,125 1605cc with 80mm bore cause parts are harder to get for the ol type. But the big bore 84 can be taken to 87 and even better would be the lancia beta 1756cc with a 9.8 comp engine from factory. Although fwd it fits straight to a 132/131 box and with a 34mm standard carb they are rated at 120hp from factory. The stroke is 79.2 which is still less than the a15 . The stroke ratio is still high rev favoured but 152 nm of torque isnt bad either. The engine sits 20 degres helping the inlets get a better flow angle but have to be sure to run the right manifold not to upset the carbs but will luckily!!!! allow more clearance for the twin carbs (heads are still taller and wider but the carb manifolds are 60% shorter than for the A series so should help heaps). With timing changes and tuned 45s another 12-15 hp are available pushing 132-135 hps at a lazy 6000rpm. All this with the smaller 41.8mm inlets. The heads can accomodate 49mm inlets and 40 exhaust which apparantely run well with standard porting!!

Guy Croft a famous F1 engineer in UK who works on these engines stresses not to open the ports unless match porting manifolds cause these heads flow so well from standard.

Still cant believe 49mm inlets and 40 exhausts! what overkill...

Almost identical engine is the Lotus BDA 8 valver used in the tradingpost rally winning Quickpro escort in Adelaide which puts out 164hp at the threads with smaller bore 83.5 and 82mm stroke but a crazy 400 thou lift inlets.

I should get 150-160 with heaps less moula and engine stress as on an A. Factory forged crank, rods, hemi cross flow head and adjustable exhaust timing seperate to inlet timing and 5 speeds laying around everywhere exposed to the sun after seeing the bodies crumble round the running gear.
I cant be that crazy or am I
Hey promise to grind away the lancia writing and cut up an L series rocker cover and put the datsun embossed bit on it.