Fellow Vettesters

I am approaching the finish line on my 350 to 454HO engine swap in a 1974 corvette. One area i did not anticipate issues was the pulleys and belt routing.

I have power steering and A/C and used all big block Corvette brackettes
If I follow the Chevy assembly manual which i would I would like to - it shows a three groove water pump pulley, three groove crank pulley, two groove power steering pump pulley, then the A/C and alternator pulleys.

The crank and power steering pulleys seem to be available, however I have not been able to find the water pump pulley. I have searched and called all the big companies no luck. The major corvette parts distributors, like Ecklers, have one that advertises that it works for 70 to 73 with A/C and PS, however for 74 it is for vehicles without A/C, According to Ecklers the vendor advises that the pulley is only 5 1/2 inches in diameter and would not turn A/C compressor at the proper speed.

So whats the poop here, 74 came with a big block that had both A/C and PS. Why is this pulley a problem. My research showed that all the big blocks for Chevy between 70 and 74 routed the belts the same, Can i use the 73 pulley or is the 73 A/C compressor different then the 74 - I think not - can a smaller pulley on the Compressor be used, is there an appropriate pulley out there somewhere, can the belts be routed another way to utilize the very available two groove WP pulley.

Looking for help, suggestions and or prior experience on this matter

Thank you for reading this very long Post

 

Came across this last night. Vintage air appears to have the 3 groove water pump pulleys.

http://www.vintageair.com/2015%20Cat...talog%2017.pdf

 

My '71 with it's 454" has the 3-groove 5-1/2" water pump pulley and it has no problem driving my A/C compressor plenty fast at idle speeds. Regardless of how large the water pump pulley is the compressor will be driven faster than the crankshaft speed.

 

Are you running a long or short water Pump if short that is a spendy pulley only seen them used around 200 s they are not reproduced cheap either .The long ones are cheaper so I had an old time
machinist shorten mine for$20

 

Thank you Mr. Sigforty Saw Your response First thing this morning. Immediately checked out the Vintage Air web site and will contact them regarding pulley and A/C combo. Of course my compressor is shot also.

What a relief now i can start focusing on getting the engine to start

Happy Holidays
Dins74

 

I agree toobroketoretire ( aaah man thats another thing i have to start thinking about)

What could be the diameter difference between 73 and 75 A/C comp a forum member turned me in to Vintage Air Which i was aware of for A/C Stuff never thought about looking At them for a pulley

 

Yes $200 plus but I was cool with that as long as it will Work

Happy Holidays

 

Your welcome. You may also want to check willcox and paragon as I see they list the 3 groove WP pulley in the $200 range.

 

MY crank pulley on my 72 with, PS,PB AC is a 2 groove. The alt is run off of the PS pump.