Those heads are a newer model year version of my 049s. Awesome heads. I put 2.19/1.88 valves in mine with bowl porting. I also polished the combustion chambers. Cleaned up the intake ports to match the gasket where it meets the intake. Amazing power. Amazing torque.
I guess it is too late to change your pistons. I am running SpeedPro H426P pistons with my 049s. They have a .100" dome on them. With the 110cc chamber that the 049/781 head has I am at about 9.6:1 compression. It is what I used as my sled puller for years and now it is going into my monster truck. When I wasn't sled pulling that engine pulled gooseneck trailers, and worked on the farm. I never had an issue with overheating or spark knock.
Your compression is going to be in the low 8s with those pistons. At your high altitude in Colorado especially, you could easily get away with the higher compression. A lot more power potential for no penalty by bumping up the compression into the 9s.
Also, if you are dropping a 454 into a truck that previously had a small block here is what you need to do..... When I did mine I used the rubber engine mounts that came with my truck. Eventually bought new ones, but the old ones worked.
HERE IS WHAT HAS TO BE CHANGED TO MAKE THE SWAP WORK CORRECTLY:
The steel, or engine side, "clam shells" must be changed to avoid your headers from hitting the frame, and to keep the fan from rubbing the bottom of the fan shroud.
Small block mounts will work but the engine sets too low in the frame in order for it to work properly. BEEN THERE DONE THAT.
Search around the internet and swap meets for GM part number 14067103. This is the steel mount used on the 454 engine from 1973 all the way up until the 2000 model year when GM quit building the GMT-400 series trucks. It is a discontinued part number but NOS parts are out there. Buy two of these. One for each side of your engine.
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