CUTLASS Long-neglected, my 1979 Cutlass Calais swap plans. Or lack of plans. Or . . what makes sense in 2021?

Status
Not open for further replies.

King_V

Master Mechanic
Jul 17, 2013
307
5
18
Sicklerville, NJ
Well, I definitely want air conditioning. Though, I imagine at some point my existing factory compressor (likely other components, too) will be replaced with . . I guess the Sanden ones are more efficient, and the most common/popular? I haven't done more than a few minutes of researching into this.

Back to the engines... I would like it to be 87-octane friendly, if that doesn't sacrifice too much in terms of power/efficiency/emissions (yeah, I don't necessarily HAVE to worry to much about that, but I'd LIKE to keep things clean and make the most of what fuel I'm burning). Since it's not going to be a daily driver, higher-octane requirements would be fine. That said, while 93 octane is very commonly available in NJ, I guess it's not in some other states, and who knows what'll happen in the future.

Now, 403 vs 455 - Let's see if I have the advantages/disadvantages right:
  • 455
    • Pros
      • Stronger block
      • No cooling problems
      • More torque easily attainable at lower RPMs
    • Cons
      • Possible hood clearance
      • Drop air cleaner may be needed
      • W/Z manifolds available, but still not as good as headers would be
      • If going headers, there are very few options for BBO in G-body
  • 403
    • Pros
      • No fitment issues, and all brackets from 260 fit
      • A little bit lighter
      • Big bore will more easily allow for bigger valves/less shrouding (if needed)
      • Better availability of intakes/a little more intake height clearance
      • Better availability of headers/more options/long tube headers
    • Cons
      • Weaker block (but not an issue for my preferred idle-to 5000-ish max RPM range)
      • Cooling problems?
      • Fewer piston options (I would guess?)

If I'm correct about the greater intake/exhaust options for the SBO, would the better intake-exhaust flow make up for the lesser cubes?

Also, does the lesser strength of the 403 make stroking (mildly) the engine a terrible idea?


At some point I will NOT be scattered all over the place on this! I swear!
 
Oct 14, 2008
8,806
7,746
113
Melville,Saskatchewan
The Olds 455 also tends to run on the warmer side, get a good rad. Your current 455 would run easy on 87. There are brackets to covert the 455 to a serpentine set up using sbc truck brackets. Also available for the 403. There are adapter brackets to convert the R4 junk compressor to a Sanden. Yeah a RPM fits on the SBO but needs a drop base air cleaner. Some have got the SBO G body Hedman headers to fit the 455. A offset ground stock crank only adds 20 ci max to the 403. I would not use the stock 403 crank to stroke, it is pretty weak. Consider the new Edelbrock heads for either, if workable for the budget.
 
Last edited:
  • Like
Reactions: 1 user

DRIVEN

Geezer
Apr 25, 2009
8,062
14,479
113
*CENSORED*
455. Build for torque at cruise RPM and don't worry about horsepower.
 
  • Agree
Reactions: 1 users

ssn696

Living in the Past
Supporting Member
Jul 19, 2009
5,543
6,662
113
Permanent Temporary
Go for torque.
FA0D9242-CD33-4368-9EED-0D053F5F523C.jpeg
 
  • Like
  • Wow
Reactions: 1 users
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor