i am very new to y bocks and while looking for my answer in a previous post here's my question : economic circumstances force me to install a 54  239 2 bbl intake manifold on a 56 272 that currently has a 4 bbl manifold , will it bolt on ???

The ’54 intake manifold will physically bolt on the ’55 and newer heads but the intake gasket seal is marginal at best.  You really do need a ’55 and up intake for the ’55 and up heads to eliminate the possibility of vacuum leaks at the intake gasket.  Where are you at?  I have the ’55 and up 2V intake manifolds and they are free for the taking if you’re in the area.  They are sitting here for both three bolt and four bolt 2V carbs.
 
Another option is to simply use a carburetor adapter on the 4V intake that will allow you to use a different flanged carb.  You don’t mention if the engine currently has the ’55-’56 Teapot flanged 4V intake or the later model (1957 and up) 4V ECZ-B intake.  In either case, making an adapter for a 2V carb is relatively simple for either intake manifold.

Lorena, Texas (South of Waco)

thank you for your reply . I'm 70 mi ne of dallas , 30 mi s of the red river , Leonard , in Fannin county.
i had to have a station wagon and bought a 1 owner 54 ranchwagon 239 , 3 speed od parked outside since 1966 . the 239 is toast but included in the deal was " running" 272 from a
56 conv , no flywheel or carburetor . can use the 239 flywheel on the 272 ?? ( it will require a new ring  gear , the teeth facing down are half rusted away . any other issues , you reckon ??
I'm 73 and worked on "old" cars since i was 17 but never had to work on a y block . ( well , i did put a one wire on a 54 239 once )

The crankshaft bolt pattern and flywheel diameters are all the same for the standard shift Y-Block V8’s.  You’ll have to watch for differences in the pressure plate and clutch disk sizes though as they vary by year and/or application.  The 239 flywheel, clutch, and pressure plate will transfer directly to the 272 if those pieces look usable.
 
I’ll suggest performing at least a cranking compression test on that 272 before installing it in the wagon.  Hearing it run would be even better.

Lorena, Texas (South of Waco)

thank you Ted , i appreciate your help