I just found this thread (having recently joined) and it's definitely got my attention.
I have a 1979 Cutlass Calais with a 260 . . and a good-running-when-pulled 455 from a 1972 Olds 98 I used to own. Of course, the motor's been sitting for about 7 years (time and no money, or money and no time. More recently, no time or money).
Due to things I'd read about clearance issues, etc., I was considering going with a 403 instead, as I know everything would fit, and BELIEVE that:
1) There's more header availability using a SB Olds (is this actually true?)
2) There's more intake manifold availability using a SB Olds (is this actually true?)
Plus, I'll admit, I want to keep my AC.
My intent with the motor is:
1) Must run on 87 octane
2) Must run deceptively smoothly
3) Regardless of whether I go with a 403 or a 455, I'm NOT going for rowdy revving - I'd like peak torque (or at least 90% of peak torque) to happen in, say, the low-to-mid 2000s RPM, and peak horsepower at mid-4000s to 5000 RPM. That's my preference, adjust for reality. I'd prefer to give up a little top end power to have a very broad, flat torque curve.
(by the way, I'm used to thinking in SAE net terms with power because, with the exception of one car, everything I've had was 1972 or later)
So, In addition to my question on header/intake availability (I'd probably just go with W/Z manifolds if I go with a 455), I am wondering:
1) http://www.robertpowersmotorsports.com/G-bodyV6-V8.html says that the lower alternator bracket must come from a 455-equipped car from the 70s. But, someone else has mentioned that, even swapping to a big block, the mounting brackets from the 260 will work with no problems. Which is correct? Do I need a special bracket, or can I use everything (not counting the A/C stuff) in terms of brackets and accessories from my 260?
2) I have ZERO fabrication skills, but since my AC is ice-cold, I want to keep the factory system. Does anyone make any kind of prefabricated brackets that will let me use my stock R4 compressor with the BBO? Barring that, anyone have an altered bracket that will let me do so?
3) I'd like to have a factory-ish looking air-box - I'm not much of a fan of the open element air cleaners - I'd go with either an aftermarket dual-snorkle enclosed one, or something that looks stock for a 455. Doing this, what are my limitations on intakes for the 455 in this car? I do NOT want to cut or alter my hood (want everything to appear stock on the outside)
Thanks....
I have a 1979 Cutlass Calais with a 260 . . and a good-running-when-pulled 455 from a 1972 Olds 98 I used to own. Of course, the motor's been sitting for about 7 years (time and no money, or money and no time. More recently, no time or money).
Due to things I'd read about clearance issues, etc., I was considering going with a 403 instead, as I know everything would fit, and BELIEVE that:
1) There's more header availability using a SB Olds (is this actually true?)
2) There's more intake manifold availability using a SB Olds (is this actually true?)
Plus, I'll admit, I want to keep my AC.
My intent with the motor is:
1) Must run on 87 octane
2) Must run deceptively smoothly
3) Regardless of whether I go with a 403 or a 455, I'm NOT going for rowdy revving - I'd like peak torque (or at least 90% of peak torque) to happen in, say, the low-to-mid 2000s RPM, and peak horsepower at mid-4000s to 5000 RPM. That's my preference, adjust for reality. I'd prefer to give up a little top end power to have a very broad, flat torque curve.
(by the way, I'm used to thinking in SAE net terms with power because, with the exception of one car, everything I've had was 1972 or later)
So, In addition to my question on header/intake availability (I'd probably just go with W/Z manifolds if I go with a 455), I am wondering:
1) http://www.robertpowersmotorsports.com/G-bodyV6-V8.html says that the lower alternator bracket must come from a 455-equipped car from the 70s. But, someone else has mentioned that, even swapping to a big block, the mounting brackets from the 260 will work with no problems. Which is correct? Do I need a special bracket, or can I use everything (not counting the A/C stuff) in terms of brackets and accessories from my 260?
2) I have ZERO fabrication skills, but since my AC is ice-cold, I want to keep the factory system. Does anyone make any kind of prefabricated brackets that will let me use my stock R4 compressor with the BBO? Barring that, anyone have an altered bracket that will let me do so?
3) I'd like to have a factory-ish looking air-box - I'm not much of a fan of the open element air cleaners - I'd go with either an aftermarket dual-snorkle enclosed one, or something that looks stock for a 455. Doing this, what are my limitations on intakes for the 455 in this car? I do NOT want to cut or alter my hood (want everything to appear stock on the outside)
Thanks....
If this doesn't solve my fuel issues, I'm going to loose my mind! :shock: Put in a little hotter Lunati Cam: Advertised Duration (Int/Exh): 262/268, Duration @ .050 (Int/Exh): 219/227, Gross Valve Lift (Int/Exh): .499/.510, LSA/ICL: 112/108. Last but not least, the Hooker ProComp headers are now going to be on the car now, I figure I might as well do it now, while the motor is out of the car... This car WILL be done by spring, so help me god! 
