My brother-in-law has come into possession of a holley 650dp.
(list 4779)with a busted base plate.I was wondering if I could use his larger fuel bowls and secondary metering plate on a spare
600 holley(list 1850) I have kicking around.I think I saw a similar
post to this earlier this year,but at the time I wasn`t paying attention.

 

Yeah it's possible, with certain limitations. You can upgrade your 600 vs carb to a dual inlet carb with a metering block, but you can't make it a 600DP or a 650 VS.

Use the secondary metering block (block off the PV if it has one, fuel bowls, and fuel bowl screws from the 650. Use the base, body, and primary block from the 600.

 

What gaskets would I use?

 

most gaskets in holleys are universal. a kit for the vs will be cheaper....and if I remember right should have you covered.

 

How about fixing the 650 instead? Proform makes a throttle base plate that would be better than the original, anyway. I wouldn't call it a "budget" item ($130), but it's cheaper than buying a new 650 DP.