Author Topic: difference between 3919840 and 3964291 heads  (Read 4365 times)

hotz

  • Member
  • ***
  • Posts: 38
    • View Profile
difference between 3919840 and 3964291 heads
« on: August 27, 2011, 07:05:46 PM »
hey guys,
Can anyone tell me what the difference is between the 3919840 heads and the 3964291 heads.??.  I have heard that the 840's produced more power and are a more desirable number. Is that because the 291 was produced in late 69 and doesn't fit may 69 cars? I have found that the 840's are a bit more $$$. Will the 291 heads make the same power as the 840's? thanks for all of your help.

rodent

  • Member
  • ***
  • Posts: 76
    • View Profile
Re: difference between 3919840 and 3964291 heads
« Reply #1 on: August 27, 2011, 11:52:31 PM »
The heads are the same :) except 291 had 1.88 exhaust valve and a tapered plug seat and the 840 had 1.72 exhaust and a flat plug seat.

 

anything