# Number 13 Heads



## riverman45 (Sep 29, 2016)

All I find list that number as a D head. It is suppose to be 1970 Ram Air 3. It has round exhaust ports, not D ports. Please help explain what I have. Thanks for helping first time Pontiac guy.


----------



## cij911 (Oct 25, 2017)

riverman45 said:


> All I find list that number as a D head. It is suppose to be 1970 Ram Air 3. It has round exhaust ports, not D ports. Please help explain what I have. Thanks for helping first time Pontiac guy.


From Wallace Racing's site :

You Searched For:
Code=13
3 Matches Found (displaying 1 to 3)
Year	Engine	Hp	Code	Valve	Misc
1970	400	330HP	13(a.t.)	2.11/1.77	75/77cc
1970	400	350HP(GTO)	13(AT)	2.11/1.77	72/75cc
1970	400	350HP(GP)	13	2.11/1.77	72/75cc


----------



## Pinion head (Jan 3, 2015)

Welcome to the forum! 

'70 model #13 heads were the big valve D port head used on the common '70 model YS & XH codes 400 4bbl engines. 
-YS engines were the base 400 automatic engines in '70 GTO's & '70 Formulas.
-XH engines were the base 400 automatic engines in '70 GrandPrixs. 
-Untouched low mile casting #13 heads will have chambers that cc in around 78cc's. Years ago, I personally examined & cc'ed chambers from several sets that their chambers cc'ed in the '78-80 cc range. Surfaced a few times, the chambers will be smaller.

Original '70 WT engines received casting number 12's & log manifolds. 
Original '70 model RAIII engines, code WS & YZ received casting #12 's, RA application Qjets, RA application distributor, and RA exhaust manifolds. 
Casting #12 Dport heads will have chambers that cc in around 72 cc. The 12's also use stiffer valve springs, originals will have a pink daub type stripe.


----------



## Shake-N-Bake (Jun 16, 2015)

riverman45 said:


> All I find list that number as a D head. It is suppose to be 1970 Ram Air 3. It has round exhaust ports, not D ports. Please help explain what I have. Thanks for helping first time Pontiac guy.


Can you post a photos of the #13 found on the heads?
Here is a photo of the two types of heads. D port on the left...round port on the right.


----------

