You could use the 5.315 rod, plenty of pistons for clevelands with ~1.250" pin heights available for some of the bigger stroker options on clevor/clevelands ( though going shorter on rod length will compromise your already compromised 4.040" bore size.)
If you use 'Yates' style nascar heads with altered valve guide placement the inlet valve pocket can be shallower & therefore allow shorter ~1.165 pin height & 5.400 rod. Ive had custom cleveland pistons made with 0.900" pin height & the top ring still 0.250" down so its not really an issue of 'you cant', but how much work/time/money your prepared to invest.
The OZ 302c heads are OK for street type applications but need a lot of work to fit windsor coolant flow plus changes to rocker pedestals, posts,chamber reshape, porting to make good power, CHI make a cast iron version of their 3v, that would be best option if it has to be cast iron..... after all that you still have to make a set of exhausts that are not going to kill all your new found HP when you try to fit it in the TVR, tough enough with windsor heads let alone cleveland design, oh & I nearly forgot, any decent intake manifold is going to shove the carb up thru the hood/bonnet, whatever you call it in jolly ol england .
