Technical SBC not performing well

I wonder, because I sure don’t know, what’s the difference is a solid v hydraulic lifter cam that lifters can or cannot be swapped?
Seems like a good time to ask

 

Solid Vs. Hydraulic Lifters - Battle Of The Bump Sticks (motortrend.com)

 

Have you checked to see if all the rocker arm's are moving while the engine is running, yet?

 

Solid cam lobes are ground with a lash take-up ramp to ease into moving the lifter up the actual cam lobe....with no lash in a hydraulic lifter, the engine sees this as a huge increase in seat duration.
Cam duration specs are just tossed out the window.

The only mix and match that does work is solid lifter on a hydraulic cam....but the lash has to be adjusted really tight, like .002'-.006" cold....just loose enough to not hold a valve open cold and prevent the engine from running, but tight enough so the no-lash ramp hydraulic cam lobe doesn't beat itself to death from lash when running.

There is an EngineMasters video of them running solid roller lifters tight lashed on a hydraulic roller cam and picking up a little power from it.
(1372) Hydraulic vs Solid Lifters: The Redux!—Engine Masters Preview Episode 48 - YouTube
Ask Away! with Jeff Smith: Can I Run Solid Roller Lifters on a Hydraulic Roller Cam? (onallcylinders.com)
Will Solid Lifters Work on a Hydraulic Cam? (motortrend.com)

 

Kind of a different subject, but aren't solid roller lifter sometimes used on a hydraulic roller cam? Probably has to be adjusted tight also.

 

Sounds like you are lost in tall grass, if you have not found a bad vacuum leak, stop , don't start ripping stuff apart, call a buddy who is sharp on diagnosis, or knows someone who is, and figure it out. Sounds like this motor has had some problems, and it might just be a timing chain that jumped a tooth or 2.

 

Newer carbs will not match the old small bore intakes.