LS3 – 525HP / Legend LGT-700 Conversion in a 66 Pontiac GTO Convertible
It is amazing the amount of work that is required on these swaps. 
05-03-2015, 05:44 PM
#44
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05-06-2015, 04:38 PM
#49
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suspension I'm in the process of putting an LS 3 / 525 Hp engine with a T56 six speed into my 1967 GTO Convertible. Ride height surly changes with the lighter LS. How much? Did you use drop spindles? What springs did you use up front? Thanks for posting a build using recent products! I am amazed at the new and better parts coming on the market regularly! I am going with the Holley 302-1 oil pan also. Thanks! DublinGTO
05-11-2015, 10:52 AM
#50
I'm in the process of putting an LS 3 / 525 Hp engine with a T56 six speed into my 1967 GTO Convertible. Ride height surly changes with the lighter LS. How much? Did you use drop spindles? What springs did you use up front? Thanks for posting a build using recent products! I am amazed at the new and better parts coming on the market regularly! I am going with the Holley 302-1 oil pan also. Thanks! DublinGTO
05-12-2015, 07:09 AM
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525 hp ls 3 How does the 525 HP LS 3 compare to the 461 as far as comfortable ability to drive on the street? Would the 480 HP LS# been a better choice as far as cruising? Thanks for responding to my prior post. Tremendous help hearing from one that has been there and done that! I am in Dublin Georgia and not a lot of resources around here to go to for this kind of help!
05-12-2015, 08:32 AM
#52
The 461 was a torque monster. Built crazy amounts of power on the low end and was fun to drive but there were drivability issues. To start, the fuel injection was better than a carb but it was a compromise. Mileage was crap even with the efi and Idle was not consistent... I was constantly searching for the best tune. It pinged unless I pulled a bunch of timing out of it. The mechanical lifters were in need of constant adjustment and I just got tired of the drama.
I don't have much time on the LS yet so my opinion is very limited. The idle is much better...cooling temps are consistent, and it cruises down the road very nicely. As I get more time on it I am sure that I will surely love it. The asa cam certainly has some rompty-rump to it but it pulls like a freight train. I have a friend that had the hot cam at first and switched to the asa cam and said it was a good decision. The downside to this is that you either need to learn to be a tuner or know a good tuner to get this dialed in. The out of the box controllers get you close but they need to be dialed in.
I don't have much time on the LS yet so my opinion is very limited. The idle is much better...cooling temps are consistent, and it cruises down the road very nicely. As I get more time on it I am sure that I will surely love it. The asa cam certainly has some rompty-rump to it but it pulls like a freight train. I have a friend that had the hot cam at first and switched to the asa cam and said it was a good decision. The downside to this is that you either need to learn to be a tuner or know a good tuner to get this dialed in. The out of the box controllers get you close but they need to be dialed in.
05-12-2015, 10:22 AM
#53
Originally wired the trinary switch to hit both grounds of the fan relays but I didn't like both turning on for the normal ecm functions so I sourced 2 additional relays with normally open and normally closed contacts. This allows independent operation of the ecm outputs when the AC system does not require fan operation. the trinary switch triggers the aux relays which open the normally closed ecm ground circuit and closes in on a chassis ground.
05-26-2015, 04:23 PM
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Ac My car had factory AC. My friend thinks I should ditch the old system in favor of the Vintage Air AC / heater system. I live in Georgia where heat and humidity are real issues in the summer. What state are you in and are you satisfied with the ability of the Vintage Air system to adequately cool the car?
06-02-2015, 10:06 AM
#55
Hell...we can't seem to get above 75 here in wisconsin for the moment. I haven't charged the a.c. yet so I am not certain. Heater works great!
My car had factory AC. My friend thinks I should ditch the old system in favor of the Vintage Air AC / heater system. I live in Georgia where heat and humidity are real issues in the summer. What state are you in and are you satisfied with the ability of the Vintage Air system to adequately cool the car?
07-03-2015, 11:08 PM
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I'm seriously considering the 525 as well, and found your thread doing a search. Sweet project!
Looking forward to reading more about the street manners of this beast and if it meets your goals for changing from your 461.
Looking forward to reading more about the street manners of this beast and if it meets your goals for changing from your 461.
08-08-2015, 07:29 AM
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Very cool project. I have a 65 Chevelle that I am thinking of doing the same thing with. Well the LS3/525 and a T56. But that is a ways off as I am boxing and narrowing the frame right now.
If you were to add up the time for the engine and trans work, how many hours do you think you have into it?
If you were to add up the time for the engine and trans work, how many hours do you think you have into it?
