g63b vs. g63bt parts???

[carguycam]

Is there a difference between the internals of a g63b and a g63bt? not could I use them on my turbo build?

[geezer101]

There are differences but it doesn't have a great deal to do with N/A or turbo. There are 2 generations of these engines - 6 and 7 bolt. 6 bolt refers to the number of bolts mounting the flywheel to the crank. The crank journals, oil pump assemblies and sumps are different between the 6 and 7 bolt engines, and the type/diameter of the head bolts are also different. There are some other minor differences but as long as you use the corresponding assemblies to their blocks it will make the conversion simpler. Are you going all out with a twin cam or going to boost the SOHC 8 valve? There are easy ways to boost the 4G63.

[DroppedMitsu]

Only diffences would be pistons(NA have bigger dome=more compression=usually not good for a turbo'd engine) and possibly oilers squirters for the pistons(they come on 4g63t blocks but not 4g63, not sure if the g63b were the same or not). As far as I have heard/read the na engines came with the same crankshafts/rods as the tubo versions(this is hearsay and coming from the 4g63t world so may not apply to the g63b versions)