THE LOBBY A gathering place. Introductions, sports, showin' off your ride, birthday-anniversary-milestone, achievements, family oriented humor.

          
Reply
 
Thread Tools Display Modes
  #1  
Old 12-03-2018, 06:04 PM
muscle_collector's Avatar
muscle_collector muscle_collector is offline
Ultimate Warrior
 
Join Date: Jun 2006
Location: Tulsa
Posts: 3,742
Default ANYONE IDENTIFY THIS BLOCK

stamped on front DS1941A
4 bolt main
casting date is C021 with the 71 cast beside the distributor hole
casting number is 481988
Attached Thumbnails
Click image for larger version

Name:	ra5 block ds1941a main cap side.jpg
Views:	651
Size:	38.3 KB
ID:	499311   Click image for larger version

Name:	ra5 block ds1941a stamping.jpg
Views:	630
Size:	42.4 KB
ID:	499312   Click image for larger version

Name:	ra5 block 481988 casting.jpg
Views:	606
Size:	51.6 KB
ID:	499313   Click image for larger version

Name:	ra5 block ds1941a date casting.jpg
Views:	642
Size:	52.5 KB
ID:	499314  

  #2  
Old 12-03-2018, 06:18 PM
Dick Boneske's Avatar
Dick Boneske Dick Boneske is offline
Ultimate Warrior
 
Join Date: Mar 2004
Location: Winneconne, Wisconsin
Posts: 5,387
Default

481988 is a '71-'75 400 block. This one was cast March 2, 1971. Interesting that it has 4 bolt mains.

__________________
BONESTOCK GOATS

'64 GTO Tripower Hardtop (Wife's Car)
'64 GTO Tripower Post Coupe (My Car)
'99 Bonneville SE Sedan
  #3  
Old 12-03-2018, 06:30 PM
A Schab A Schab is offline
Chief Ponti-yacker
 
Join Date: Mar 2009
Location: Spokane Wa.
Posts: 754
Default

SR block ?

  #4  
Old 12-03-2018, 07:25 PM
unruhjonny's Avatar
unruhjonny unruhjonny is offline
Ultimate Warrior
 
Join Date: May 2004
Location: Calgary, AB, Canada
Posts: 6,232
Default

/\/\ that's my guess.

the second picture appears to not have an application code or EUN.

__________________
1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.


1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
  #5  
Old 12-03-2018, 07:44 PM
tom s tom s is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

DS is "usually" a engineering block.Can you post a pic of the lifter bore area and the back of the block?Tom

  #6  
Old 12-03-2018, 08:06 PM
'ol Pinion head 'ol Pinion head is offline
Ultimate Warrior
 
Join Date: Apr 2000
Location: INJUN Territory, Red State Merica!
Posts: 9,564
Default

Agree with Tom S.
DS typically meant "Developmental Series" as in a Pontiac Engineering piece

Get that years ago from Ron Aycock, he had a few?

__________________
Buzzards gotta eat... same as worms.
  #7  
Old 12-03-2018, 08:39 PM
sdbob sdbob is offline
Ultimate Warrior
 
Join Date: Aug 2003
Location: Latrobe,Pa. USA
Posts: 2,538
Default

Are my eyes deceiving me, that distributor bore looks offset and looks like V or SD size.

  #8  
Old 12-03-2018, 08:48 PM
tom s tom s is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

Does not look like the large one to me from the pic.Tom

  #9  
Old 12-03-2018, 09:21 PM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

photo titles assume RA V

you're welcome, Capt. Obvious

  #10  
Old 12-03-2018, 10:27 PM
Held for Ransom's Avatar
Held for Ransom Held for Ransom is offline
Ultimate Warrior
 
Join Date: Mar 2000
Posts: 8,912
Default

There looks to be a stamping under the cast "71".

__________________
So long, farewell.
  #11  
Old 12-03-2018, 10:37 PM
Rocky Rotella's Avatar
Rocky Rotella Rocky Rotella is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Omaha, NE
Posts: 2,686
Default

I’ve seen where Pontiac cast 400 blocks for high performance applications and used the basic 481988 as the basis.

I’d guess this to be a special run for engineering use or possibly something destined for SR based on the distributor hole, which looks like it accepts the large distributor gear. It may be for a tunnel port engine.

What does the lifter galley look like? And where are the cylinder wall valve reliefs located on the deck surface?

  #12  
Old 12-03-2018, 11:17 PM
muscle_collector's Avatar
muscle_collector muscle_collector is offline
Ultimate Warrior
 
Join Date: Jun 2006
Location: Tulsa
Posts: 3,742
Default

I actually have two of these. identical dates, identical ds numbers. one however has drain plugs at the front lower sides. really weird.

  #13  
Old 12-03-2018, 11:22 PM
Rocky Rotella's Avatar
Rocky Rotella Rocky Rotella is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Omaha, NE
Posts: 2,686
Default

Do you know the bore diameter? And did you purchase both together?

  #14  
Old 12-04-2018, 08:54 AM
muscle_collector's Avatar
muscle_collector muscle_collector is offline
Ultimate Warrior
 
Join Date: Jun 2006
Location: Tulsa
Posts: 3,742
Default

its a 400 matter of fact the other block has 400 cast on the side of it. ill try to post pics of it if I get home in time tonight.

  #15  
Old 12-04-2018, 09:55 AM
johnta1's Avatar
johnta1 johnta1 is offline
Ultimate Warrior
 
Join Date: Feb 2001
Location: now sunny Florida!
Posts: 21,237
Default

Tell us if the distributor hole is normal size or larger?
Also no extra casting ribs in lifter valley?
(as others have said)



__________________
John Wallace - johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

Winner of Top Class at Pontiac Nationals, 2004 Cordova
Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats

KRE's MR-1 - 1st 5 second Pontiac block ever!


"Every man has a right to his own opinion, but no man has a right to be wrong in his facts."

"People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates
  #16  
Old 12-04-2018, 12:40 PM
tom s tom s is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: long beach ca usa
Posts: 18,764
Default

Guys,with me getting involved in this V stuff,over the years I have seen so many diff DS and engineering stuff and there is no true rhime or reason.The early all alu pontiac engine I found way back in 1964 and finally owned used a early block with a 61 and later bell pattern,the only one ever seen.The alu V block was a engineering reject and was pulled from the trash.I have owned a RA V 400 block with a transfer lug,my 366 block had the joined lifter bore but no dry sump provision.Barry had a 303 std deck with the dry sump but no joined lifter bores.The 303 std deck I just bought is 4 bolt 70 400 block.I have never owned a splayed main block,Wade at BOP has some unusual DS stuff on his site.I NEVER say never about engineering and DS stuff.My guess with the non lifter bores on std deck 303s were they were never going to get enough cam in one to hurt it.The 303 short deck V was the block our hobby could use for the boosted guys these day.Maybe the strongest pontiac production block IMO.Tom

  #17  
Old 12-04-2018, 01:15 PM
unruhjonny's Avatar
unruhjonny unruhjonny is offline
Ultimate Warrior
 
Join Date: May 2004
Location: Calgary, AB, Canada
Posts: 6,232
Default

this is all so cool!

__________________
1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.


1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
  #18  
Old 12-04-2018, 01:25 PM
sdbob sdbob is offline
Ultimate Warrior
 
Join Date: Aug 2003
Location: Latrobe,Pa. USA
Posts: 2,538
Default

John Herslow told me that Pontiac had given him at least 1 or 2 HD 400 blocks. This was late 70s early 80s when I bought some parts from him. Didnt say for what applications but he was trying a SM ,super modified Firebird at one time. Not sure whether,A,B,or C SM.

  #19  
Old 12-04-2018, 02:08 PM
John Eiseman's Avatar
John Eiseman John Eiseman is offline
Senior Member
 
Join Date: Dec 2009
Location: Woodland,Wa.
Posts: 232
Default

Subscribed...

  #20  
Old 12-04-2018, 07:16 PM
muscle_collector's Avatar
muscle_collector muscle_collector is offline
Ultimate Warrior
 
Join Date: Jun 2006
Location: Tulsa
Posts: 3,742
Default

here are the pics of the other block (I refer to it as the "blue" block)

I got the first one pictured from mickey thompsons family member back around 80 to 81 when I bought all kinds of high perf stuff. (swiss cheese engine, early sd heads, intakes, experimental junk, fuel injection set ups, one of the 4 cylinder sd engines that he ran in that shorty rail dragster, list goes on and on). it was marked ra-5 as you can see in one of the pics.


note the weird plugs on the front side of the block that this one has but the other one doesn't. also has something stamped above the casting date that I cant make out in the picture and honestly never noticed it until I was downloading the pics.
Attached Thumbnails
Click image for larger version

Name:	ra5 block blue ds1941a stamping.jpg
Views:	527
Size:	35.7 KB
ID:	499369   Click image for larger version

Name:	ra5 block blue casting number.jpg
Views:	523
Size:	58.1 KB
ID:	499370   Click image for larger version

Name:	ra5 block blue casting date.jpg
Views:	522
Size:	69.5 KB
ID:	499371  

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:20 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017