sbc running too warm

[dogsofwar]

My 305 seems to run around 235-240 (factory gauge) and that's going down the road, it never seems to reach the red though. It does have a flex fan on it. It was missing the fan shroud, so I put one on. Put in a new sending unit. Heater works great so I am assuming that the water is circulating fine. Thermostat wasn't working, replaced it.

A little history, the po (or one of the po's) had trouble with it overheating, so they rigged up some non-working gauges, replaced the thermostat (i think), put the sending unit wire underneath the valve cover, taped up the connectors from the guage inside the cluster, installed flex fan. Basically a mess. Once I got everything working, I think the main trouble was a bad thermostat, wasn't circulating any water. Fast forward past a blown head gasket, I put new heads on it, but the guage is still showing hot. I am running headers, can they heat up the brass of the sending unit enough to give false readings?

Any other suggestions on what I should try next?

 

[Fordum]

When in doubt, doubt the gauge. If the po did that much, he may have farucked the gauge too. See if you can borrow a known good mechanical gauge for a day or so and see if you are really running that hot.

 

[kd7kmp]

I agree with Fordum...get an accurate gauge on there and check temps again. The factory gauges are not the most reliable.

Kevin

 

[dhcomp]

I picked up an aux temp gauge at walmart or somewhere on clearance for under $10.

My point being, you can probably pickup a super cheap one at kragen or somewhere to verify yours against.

 

[dogsofwar]

I've got an extra gauge, can I just wire the positive up to the battery and the other to the sending unit as a quick check?