65GS.com - Buick Gran Sport Enthusiasts!
Drivetrain => The Dual Quad => Topic started by: 65gsrag2x4speed on March 03, 2009, 03:13:49 PM
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From understanding the 2x4 did not come from factory on any gs? This was only a dealer option? Anyone know what the horsepower numbers changed to after installing the 2x4 option?
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HP goes from single 4v @ 325 to 360hp with 2x4.
The dual quad was a dealer only add-on for '65. I read somewhere ,a long time ago, it was a factory option in '66.
Maybe Walt has more input on this.
Loren
2/28/18 update memo.
I came across recent discovery of a Buick service bulletin that states that the 2X4 set up was NOT available as a factory option on the Skylark Gran Sport in either '65 or '66.
Service bulletin number 620 Group 64 dated April 15, 1966
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Ok thanks for the info.
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Loren,I'm not sure 360HP is a true statement from just a 2X4 add on.In 65 when you ordered the Super Wildcat from the factory it was rated at 360HP.It also included 2 1/2" exhaust,recurved distributor and a couple other mods.I'll check and get back to you.
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Loren,the 401 was rated at 325HP where as the 425 was at 340HP and when you add the Wildcat option it jumps 20HP to 360.I don't know what a 401 with just a 2X4 addition would add in HP but I'm pretty sure it wouldn't push it to 360.
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Dont worrier when the carbs open up its the best sound you ever heard.
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thanks everybody. I was hoping to get atleast 400 hp out of my 401. With a edelbrock intake and two 600 carbs,headers,2 1/2 exhaust, msd distributor and box. What do you guys think? I pulled the oil pan and valley pan my motor has definately been redone not many miles ago.
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Your right, I was a little confused. Thanks though.
Loren
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thanks everybody. I was hoping to get atleast 400 hp out of my 401. With a edelbrock intake and two 600 carbs,headers,2 1/2 exhaust, msd distributor and box. What do you guys think?
There were a few dyno results posted on V8Buick in the past year. Even builds with small-stem valves and port work could not break the 400 hp barrier. 350 to 385 hp is where they generally dyno. The problem is, the horsepower maxes out at 4800 rpm or so. The heads simply do not flow enough air to let the engine make good power at higher rpm's.
Don't worry too much about the numbers. Nailheads have lots of low-end torque and that makes them great street engines!
For strip use, mid 13's are possible.
A reliable source tells us that Edelbrock has at least two designs for aluminum Nailhead heads in development. Only time will tell if they actually make it to production.
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The dual quad was a dealer only add-on for '65. I read somewhere ,a long time ago, it was a factory option in '66.
Maybe Walt has more input on this.
Loren
For 1966, the dual quads became a factory option on the 'big' Buicks only....but only till the model year was half over....Feb '66 or so.
The Skylark GS had it's own engine option. It was a 340 hp 401 with a Q-jet carb, different cam, and the 2x4 spec distributor.
There was also a 'race' option avail in 1966! It featured the above mods with 11:1 compression. I know one guy that found (and purchased) 2 of them in the last few years.
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Ask and you shall recieve!
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thanks again everyone 8)