Chevy 235 6 cyl.

Can the hydraulic lifters be replaced with solids ?
Any suggestions on over heating ?
Has new radiator, water pump, themostat and hoses.
Cools fine on road, over heats quickly while idling ?

 

1 Yes but you need to change the cam also.
2 Check timing, Have cooling system checked for combustion gas [cracked head bad gasket not to likely as it cools going down road] Fan pulling air through radiator [not one made for reverse rotation] Heating at low speeds is almost always a lack of air flow -retarded timing issue.

 

That's what I was gunna say. Do you have a shroud on the fan? If not, get one. It make a WORLD of difference.

 

Only 58-62 blocks were drilled to run on either solids or hydraulic lifters, which look almost alike in those years.
Earlier blocks are either solid or hydraulic bore, with different size lifters.

Some have done it, but not a good idea to run solids on a hydr. cam.
On hydraulic cams the lobes don't have 'ramps' like solid cams, giving a gentler lift and drop.

If you had overheating from valves not getting cooled enough, it would be a problem at higher rpm, not so much at idle.

 

All 235's are able to run solid lifters.

Its on '57 and earlier blocks that you can't run hydros in place of solids because the lifter bores aren't cross drilled. Only blocks that had hydros to begin with can run hydros ('57- earlier). 58-62 can run either as they were all cross drilled.

I have been told, and I seem to recall reading on a comp cams info sheet, that it is possible to put solid lifters on a hydraulic camshaft, but not the other way around. Personnally, I would change the cam also.

If you have the tips of the rocker arms resurfaced, you can eliminate most of the valve noise associated with solid lifters.

Hot idle,
Define what "hot " is.
What temp is the thermostat?
What year is the engine, and what is it installed in?
Sometimes new engines can get hot quickly at idle due to not being broke in yet, but this isn't a new rebuild, right?
Retarded timing, due to either not enough initial timing, or a disconnected vac advance. If the vac advance isn't working, you can dial in some more initial timing until you can find a replacement vac advance.
Air flow through radiator/engine compartment not suficient to do the job.
cracked head.