Cold start hesitation until working temp is achieved

[kilroypr]

To make the story short. This is the 3rd engine on the car.
The OEM died because over reving on tranny that went to neutral.
The second one a Mr. Goodwrench remanufactured one died at 1/4 mile.
Beated up the crap out of a GT Stang but at the 3rd pass the clicking sound at trap meant pistons 3 and 5 broke.
The OEM with 195degf tstat and OEM plugs could run out of the driveway just started in the morning without problems(there was no need to engine heat up), the Mr. Goodwrench with 180 degf tstat, DHP PCM V1.0, 3.4" SC thrasher pulley, Headers, Champions 408CP(Autolites 104), SLP Headers, Thrasher CAI and few other things started the same way as the OEM. Just crank it on and off you went.
Now the new one got the same beef the Mr. Goodwrench got excpet that now instead of using Champions I am using AC/Delco plat plugs wich are 2 heat ranges cooler.
I have to heat up the car for at least 5 minutes to be able to drive it properly. Ripn12s pointed out that could be related to the plat plugs being cooler but neither he or I are certain about this. After the car heats up is really strong, even stronger than before. But this cold startup thing is really anoying. Any comments on this?

[Slade901]

It looks like spark plugs to me.
Make sure it has a correct gap. Most autoparts stores they tell you that it has the correct gap but most of the times it does not have a correct gap and I have to re-gap it myself.
You might have to use a stock spark plug just for comparison and see if what happens.

[kilroypr]

They all are gapped to .55". And Ripn12s just told me the same thing to rule the plugs out. But since the car after heated up runs a lot better than with the previous engine I will leave it like that.
Just to see what people think and what they have done besides returning to the OEM plugs. I am running cooler plugs to lower KR and the car usually even under mild load the KR is almost 0 and at wot is +/- 1.5deg. Before would be 2 at mild load and +/-4.5deg, so now the KR behaves a lot better.