I have a set of TFS 170 heads 58cc and stage 1 TFS cam, 24lb injectors and matching MAF, and an intake from an Explorer........I am going to replace the shortblock because I am losing oil pressure after it warms up now and I am not sure if I should stick with a 302 or go up to a 331 or 347. I will NOT be racing the car, it's a 1 owner 90 GT and I want it more as a car I can get in and drive anywhere than to beat someone for 1/4 mile. Summit has a short block 331 or 347 by ATK for about $2400, does anyone know if they are any good? The heads and cam are about a year old, I put them on the 5.0 Explorer block after breaking the crank in the original 5.0 and needed an engine for it quickly, now I want to get the parts matched up right and have it as a nice street car with more power than stock, any advice?