what are they and y install it? i am building a 306 with afr heads and i see these on a lot of high end motors. but just dont know if its worth the $$$.
I knoow the girdle is to help keep the block from twisting under high horsepower conditions. Helps stop internal binding and helps from splitting your block. A MUST if your are running a stock block and putting alot of ponyies behind her
a main girdle wont make the block any stronger, if the block is going to break... it weill break regardless of a girdle. what a girdle will do it keep things together when it does break so it promotes a better chance of not totally trashing the bottom end if the block splits or what have you.
a windage tray just shields the crankshaft from slinging oil in the crankcase. there is alot of "wind" in the crankcase. the crank is spinning fast and it just flings oil all over the place. this oil flys all over the crank and produces a parasitic loss of power. but its very small, i think you may a notice a few horse on a dyno. but a windage tray makes the most difference on like a roundy round modified, that runs 8-9k constanty and run alot of oil, it gets to be a mess, mods can only run wet sump IIRC so they do what they can to keep the oil away from the crank.
sprint cars or late models run dry sump pans which is better all around than a wet sump but the whole setup weighs more and is more complicated.
for a street car i doubt you would notice a power jump with a windage tray, a street car just doesnt see that high of rpm long enough etc. but if its apart and you can get one, why not eh? its those little things that add up and give you the small edge over the other guys.