no
the 403 is a smallblock with a big block bore. the bore is actually bigger on a 403 than it is on a 455
If it is a V8 it will be a 4.6L motor, it is niether it is a modular engine and they are not classified in the usual big block, small block engine sizes. It is just it.
They dont make a 350 big block.The big block starts at 400. Wrong! 400 is still a smallblock. Big block Chevys start at 396, but does not include the 400, which the heads/crank and starter/etc. fit on the 350/305 etc.
No it is not completely different bolt pattern and dimensions
It is the water hose thast goes from the intake manifold, into the water pump. It by passes the thermostat.
That is a by pass, so the water can transfer around the thermostat.
pretty much any 454 exhaust manifold will fit
remove old engine and install new engine including exhaust and accessory brackets and pulleys. everything should fit. be sure to use a 454 flywheel with 454. smallblock flywheel will work on 396,402,427
It could be done with high compression, big valves, and a roller cam, or a supercharger, or nitrous oxide.
It's based on displacement, yours is 305 cubic inch which is a small block, big blocks are usually up above 400 or so You're right, a 305 is a smallblock, but the difference between bigblocks (bb) and smallblocks (sb) is NOT entirely based on displacement. Although it would seem that increasing displacement at a certain point draws the line between a sb and a bb, this is not the case; i.e a gm 396 cui is a bb whereas the 400 cui is a sb. The reason for this is that the difference is based on the (physical) size of the block itself,-as the manufacturer in this case traditionally operates with two different sized v8 blocks, one was named smallblock, the other bigblock. So, in the end the difference here is something one has to look up in a manual and then remember for future reference.
If it is a stock motor then yes it is. 600 CFM carburetor will be just fine on a stock engine.
Big block