Question About 351 Heads

[dr hook]

So through some bartering I've been slowly collecting some parts. I got a bunch of stuff from a buddy of mine, which included a set of heads. He told me that they were "Really well ported/polished E7 heads. Good valve job, double valve springs". I didnt even look them over as I loaded them up. Turns out... they are 351 heads. The numbers are D80E.

Things I have waiting to go on the car:
Ported GT40 intake
TrickFlow Stage1 cam
65mm tb

SO, from what I've found... these heads will make less power on my little stock 302 because of the larger combustion chambers. So basically I have no use for these. Is that correct?

 

[Dart68]

So through some bartering I've been slowly collecting some parts. I got a bunch of stuff from a buddy of mine, which included a set of heads. He told me that they were "Really well ported/polished E7 heads. Good valve job, double valve springs". I didnt even look them over as I loaded them up. Turns out... they are 351 heads. The numbers are D80E.

Things I have waiting to go on the car:
Ported GT40 intake
TrickFlow Stage1 cam
65mm tb

SO, from what I've found... these heads will make less power on my little stock 302 because of the larger combustion chambers. So basically I have no use for these. Is that correct?

The effect on power output will depend on how much lower your CR is compared to the 302 heads. You may find the difference is actually minimal. What's more important is flow characteristics. Notice I said flow characteristics and not max flow. The area "under the curve" at a targeted RPM is more important than max flow at max RPM. In the end if you're willing to spend the money there are better heads available.

 

[rd]

I think D80E heads are the common 70s stock heads, and are the same casting as 302 heads except 351s have have larger (1/2 in) head bolt holes. Iirc all of them have 70 cc chambers and 1.78 intakes and 1.48 exhaust valve sizes. I ported a set once a long time ago, and they did pick up a couple tenths over an unported set of the same. They were the stock head on my 79 5.0 Capri, 140 hp two barrel. However, these days there much better stock style heads, Gt40s, p heads, etc. You may find that by the time you spend money do a valve job and install decent springs, you are in the same price range as much better ones.