In my car im running the Red Top TVIS, which is in pretty good knick but would still like to rebuild a bottom end to have a 100% fresh and reliable motor, and also to learn a bit more about the insides of the 4AGE. My motor has the bigger bottom end with 20mm gudgeons and no oil squirters, and the big port head, and runs the red top loom (different to blue top).
My idea is this, rebuild a blue top block with new pistons etc, then once built swap the blue top block over for my red top, and run with my existing Red Top Head and Loom either using a TRD head gasket or new stock depending on piston dish. My reasons for wanting to use the blue top block are..
Very cheap in comparison to Red Tops, i.e blocks, new pistons etc.
To get that 4AGE Feel and revvyness people say the lighter blue top has over the Later model blocks.
Are there any problems with this idea? Is the blue top considerably weaker? (Im not particularly hard on motors and is primarily street driven, will be perfectly looked after) Not modified, just blue top cams, and adjustable cam gears, and bit more compression.