what do you think about this engine combo

Engine is a 74 Z1 I have a welded crank from a z1 to start the bottom. 900 head with 1075 10,51 compression. 390 lift cams. ported head under buckets on exhaust' stock valves. Any thoughts?

Sounds like what i want to build-see abused z1-900 post. Can you tell if the block has been clearanced-machined for the cylinder to fit in the block. Is the cylinder original?

I have a 903 head bored out to a 1075

You mean 900 block bored to 1075.
1045 is max on std liners but leaves the walls too thin for my liking.
It must have had 1015 liners fitted to get the 1075 capacity.

you will be really happy with it i have pretty much the same combo in my 74 last time i dyno'd it i got 114 horse and 79 ft lbs of tourque really responsive quick street motor i use 29 smoothies and a yosh pipe really reliable and have put many miles on it lots of trips too been to sturgis with it 3 times

peter1958 wrote: Engine is a 74 Z1 I have a welded crank from a z1 to start the bottom. 900 head with 1075 10,51 compression. 390 lift cams. ported head under buckets on exhaust' stock valves. Any thoughts?

Pretty standard issue stuff for a nice boost over stock. Should make a nice ride that's very easy to tune, smooth and reliable....