What is with this impression I am getting where people want to pay less for 1997 heads than any other year?
Seems all the research I did in the F/S section I see post after post of those who are wanting casting numbers and then offering significantly less money for the asking price and even those who specify, "If they were any other year I'd take them..."
So... what ground breaking discovery did someone make as of late from a cylinder head that's been out 8 years?

 

To begin with, I don't know. I will say though that I have seen posts here that say that the older heads have more material to work with when porting, etc. Now whether that translates into getting more flow, I can't say, since it doesn't seem to make much sense to me. Maybe when they are ported, you can remove more material without getting into the cooling passages or whatever.

 

not exactly sure but i remember reading a post a while back where someone said the 97 lt1 castings were harder to work with and there wasn't as much material to remove or something like that.

im sure someone else will know for sure though.

dangit, just posted a few sec after, lol.

 

I believe if you want an all out max port job the 93-95 casting has more material to work with, but i think for most peoples street applications the 96-97 head works fine. I think most people hear the 93-95 is better for porting so they want it. Advanced induction use to have listed on their site an all out race port which was above most peoples "stage 2" heads that most of us are running. I believe that is when the 93-95 casting is desired.

 

The 97 and late 96 castings are a lighter weight casting that out of the box flow more... problem is they are not as good for porting so a set of ported 92-early 96 castings are a much better place to start from.

Bret

 

Yeah the 97's 561 cast heads flow about 10% more CFM than the 93-95 LT1 heads. Though the 93-95 heads are better for porting because they have more meat.

 

Are there any links or articles of any kind to back any of this up?

 

Yeah, sstrokerace is a machinist and what these boards say and from what Ive gotten from conversations with him, he knows exactly what he is talking about. Very intelligent person when it comes to these engines and their workings.

 

While all this may be true: show me some results of porting pre 96 heads v. ported 96/97 heads with regard to flow results.

 

Just when you thought you've heard everything there is to know about the LT1, along comes something most of us never heard of.
That means if you go to a dealer or Dal, to buy a set of LT1 heads you have to specify the year, eventhough any year would fit just fine?
-Goose

 

Exactly...
In trying not to question anyones' abilities or intelligence or experience I still find it hard to believe that only after eight years has this comparo surfaced to find such differing results between heads of different years.

 

Call up Lloyd sometime.... I saw the different castings first hand and he has the flow sheets to prove it. In fact all you would have to do is search for it and I'm sure you will find it.

Bret

 

Lloyd brought this up in a thread he started just a couple weeks ago, exactly as Bret said. I have a set of #561 casting('96-'97) heads and a set of pre-'96 heads at my shop...there are distinct diffrences. I went and researched this after it was brought up by Lloyd...yes the 561's are thinner.