Are you running stock manifolds or headers? Headers coated inside and out run a lot cooler on my stuff.
As mentioned, check your under hood seals AND let us know what your timing is at both initial and total. Also, curious what is your A/F readings at idle and cruise?
Reasonably priced laser temperature guns are readily available on-line.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's
1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
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