I Have an EL XR8 with 347 stroker. It has SVO ally heads , Roller rockers, Roller cam, Explorer intake, Twin system, and piggy-back computer. Throttle-Body is 70 mm Tickford. AU I think. Mass Air Flow sensor is standard. I do however have 80mm TB and 75mm MAF . I would like to know if I should just use the larger MAF with 70mm TB as I have been told MAF should be bigger than TB or will I still get some gain using The bigger TB with slightly smaller MAF. when measured MAF is actualy 77mm but manufacturer says 75mm.

I would put the 75mm MAF on and leave the throttle body as it is.
That would be a good combination.

I would probably stay with the 7omm tickford throttle body and use the larger MAF you suggested.

We need more detail. What heads exactly? What cam exactly? Is the intake unported?
Piggy back..Yuck but, which one exactly?

I wouldnt be upgrading T/B on the explorer manifold. Go for a different manifold and then maybe go for a 75mm T/B. But as Pete says we need more info as in heads, cam etc, as a manifold and T/B upgrade may not be required.

OK,
The thing is I live in Tassie and I brought the car of a fella in Waga Waga NSW. It had all the engine mods done allready and had only about 20,000 Ks on engine after rebuild. I have no idea of exact specifications which I know will make things very difficult. The camshaft is very agressive and computer is CSI ( computer solutions industries ) The engine is only running stock 18psi injectors . I am trying to hunt down a set of blue top 24psi as the MAF I am going to fit is calibrated for the blue tops. I had the car tuned on dyno a while back and it only Put out a touch over 200kw at wheels. I am hoping that improving induction with K&N filter , MAF (PRO.M Racing) and maybe TB along with updated injectors and perhaps fuel pump and Regulator I can significantly improve Horse Power. I will see if I can find last Dyno sheet and give some figures off it.