Pontiac Ram Air IV, 455 H/O question - Lateral-g Forums

**Ummgawa** · #1 02-10-2006, 03:43 PM

I need some clarification. I have been looking for a set of 455 H/O heads. I assumed they were Round port heads like the RAIV heads. I founds a set and asked the guy a lot of questions and the last question was if they are round port heads. He said no that the 455 H/O came with D port heads and no Ram Air exaust manifolds,just log type. Well, that was a surprise to me. I thought he was BSin me to sell me some heads but now, on the wicked Judge Vert thread on the Ebay ad at the bottom, there is a simular question and this guy asks:

Q: Awesome car, way out of my league. Have casually known owner of 1 of the other 455 Judge converts, bought from supposed original owner in 75. Believes the driveline was untouched. The thing is, his car had HO exhaust manifolds on it. He has the Build Sheet, original window sticker, etc. although he has been unwilling to share them. His was also built fairly early, has YA code motor so built before the switch to the YC code around MUN 210000. Anyway, I'm interested in knowing if your car has HO or regular log manifolds. I'm also be interested in knowing what the Build Sheet says at the bottom. So very few of these cars were built, it is difficult to learn much about them. There is much confusion about the availability of the 455 in the Judge. Base Judge was RAIII but the Ram Air was a separate option for the 455, it isn't clear if the Ram Air was automatically included with the 455 Judge package. Same for the HO exh manifolds, could they have been included too?
Feb-09-06

A: HI MY JUDGE DOES NOT HAVE RAM AIR EXHAUST MANIFOLDS. I DONT THINK ANY OF THE RAM AIR 455 IN 70 HAD THEM.I HAVE A 70 455HO RAM AIR CONVERTIBLE ALL ORIN IT ALSO DOES NOT HAVE RAM AIR MANIFOLDS. BUT IT DOES HAVE ON THE BUILD SHEET THE EXTRA CHARGE FOR THE 455 AND THE RAM AIR OPTION. IT CAME WITH A RAMIV CARB.FROM THE FACTORY NICE TO TALK TO YA. GARY

Charley, Bill, Jonny or any of the many Pontiac Guys, any heads up here?

**jonny51** · #2 02-10-2006, 04:22 PM

Jim I am pretty sure the RA IV,HO and SD heads are all round port.The SD's were worked for more airflow or something like that

**andrewb70** · #3 02-10-2006, 04:34 PM

I belive that in 1970, the 455HOs had D-port heads.

Andrew

**jonny51** · #4 02-10-2006, 04:41 PM

After looking around I think you are right Andrew.

Smack_talker · #5 02-10-2006, 04:42 PM

H.O. and SD heads are D-ports, I think. I know SD heads are D-port not positve on HO. Do you have the casting number? That would tell you what it came on.

**Ummgawa** · #6 02-10-2006, 05:06 PM

I have seen a SD 455 motor with Round port heads. The D ports on the 455 H/0 surprises me, though. Thanks for all the help and knowledge. I went to a few Pontiac sites and no help there either. A few "let me get back to you on that" replies.

**Ummgawa** · #7 02-10-2006, 05:13 PM

MORE CONFUSION!!

See this article on the 455HO and the Super Duty:

http://www.highperformancepontiac.com/tech/pon_0505_sd/

Down where the picture of the 455 SD head is-

The round-port SD-455 cylinder heads were similar to those found on the R/A-IV and 455 H.O. engines but with revised intake and exhaust ports for even greater flow.

**jonny51** · #8 02-11-2006, 12:19 AM

I got this off of another site...

The1970 455 HO had D port heads, 4 bolt mains, cast iron intake, factory cast headers, nodular crankshaft, 60 PSI oil pump, for 1971 the 455 HO had the aluminum intake, round port heads, cast iron headers, 4 bolt mains, nodular crankshaft, 60 PSI oil pump.

ProdigyCustoms · #9 02-11-2006, 05:13 AM

I just sold a set of dated correct 71 HO heads from Kevins (Jagarang) Firebird motor. I still have the manifolds and they are round port.

**jonny51** · #10 02-11-2006, 05:23 AM

Quote:

Originally Posted by ProdigyCustoms

I just sold a set of dated correct 71 HO heads from Kevins (Jagarang) Firebird motor. I still have the manifolds and they are round port.

I think they switched to 0 port in 71 on the 455HO.