The 250 x flow are a really good cheap donk,especially the xd,xe,xf era
Free to a coupla hundred will get ya a complete running falcon
They looove the juice,always have
Comparing the engine cost Vs conversion cost ,6 cyl against V8
V8 would be the better option
Compring a 4.1 L petrol against an SD33T,well would ceratinly be a good little test
Money is on the SD
Comparing the L28 petrol against the x flow well thats different
Really depends what sorta vintage x flow your chasin,pre EFI,post EFI ect ect
Comparing say and old school x flow against an old school hemi 6,the hemi will absolutely smash the x flow
Then again so will the wallet cope a hiding running the hemi
The new later model falcon motors are the go
i looked online to the hp/torque and the older xflow has better torque at lower revs
i was thinking the ohc type and puttin holley etc and modifying xe dizzy tofit but at 2300 rpm for the peak torque on the old xflow thats pretty good add decent cam extractors better carby and would be pretty good
i used to have an xc falcon with an awesome 250xflow was a pretty quick car
Not 100% certain,but mixing and matching inlet manifolds between older motors and newer motors
Could have issues with the port design ect
Youve determined nothing injected
So id be looking for an XE 2V (factory 2 barrell) motor,althought it would be electric ignition
The duks guts is the newer falcon turbo donks
Man these have lots of power
Know of a few 12 sec street cars,and very docile for street duty
Well over 500 KW from these
The alloy head xflow from late xe and early xf i believe to be the best to look for.
They are the last of the leaded models (but can run on unleaded anyway - this was just before all the unleaded fuel was being used). All alloy head models can use unleaded - alloy heads came in half way through the XD model but the xd alloys still used the single barrel stromberg. earlier xe heads still had the smaller valves as the cast iron head models.
The engine to look for should have a "'C1 or C1a" cast into the head in between the 1st and 2nd inlet ports.
The later xf has C2 cast there and that is known as the unleaded model, these ones do ping badly using 91oct fuel, also the electronic distributor is not as simple.
the c1 head engines are best i believe as:
-They have larger inlet valves and the manifolds are already fitted with 2bbl weber adm34.
-Simple module type electronic distributor.
-weight 18kg less than cast iron models.
If you use and earlier cast iron head model you can fit an allloy head later to it, but use the C1 head as the C2 will give way too much compression (it has a small chamber).
Note though, the cast iron has different intake and exhaust bolt patterns and they are not interchangeable with alloy heads (but you can get multi fit extractors.
been researching this for myself for a few months now.