rs34 or VM29

[Guest]

Back story:
I picked up a basket case 77 GS750 that I've been assembling. VM29 Smooth bores, Yoshimura (.353?) cams, Weisco 844cc 10.5:1 Pistons, Ported head, Ape Valve Springs, and a 4 into 1 of unknown brand. I'd gotten the block assembled and and the head on. When measuring the valve clearance every valve had <0 clearance. Thinking nothing of it I pulled the shims finding that they have been ground down. Every shim was 1.83-1.89mm. Damn. Feeling defeated about not using the trick ported head out of the box I jumped on FleaBay and ordered a extra head to get this bike running. When the package shows up its actually a gs850 large port head. Its in awesome shape but the 33mm ports are a huge mismatch to my 29mm smooth bores. I'd like to use this head as its in great shape so I was thinking about picking up some Mikuni RS34's.

Questions:

Given the mods and the large ports will I be able to get RS34's running well or is the engine just too small?

Will putting the VM29's on the large port head cause flow issues or power loss?

Advice on another path?

Thanks,
Ron

 

[Big T]

1. RS 34 should work
2. Poor cylinder filling with a large port
head
3. Disassemble ported head and have valve tips trimmed by a machine shop. Should be able to remove .5 mm, which gets your shims back to 2.3 or so