[18.2SS.1LE]

Originally Posted by ZLRob

Remember the old saying, "torque wins races, HP sells cars?"

Just to give you an idea of what that looks like, the majority of the aftermarket cams being sold out there get you big HP numbers at the expense of considerably lower TQ numbers. I see it in all of these guys builds all the time, 760 RWHP/ 684 TQ (example). The lack of pulling power over the band. The LT1 cam gave me a great increase in HP capability yes, but what really got me was the high TQ numbers. Though it didn't surprise me either based on the lack of lift the exhaust has compared to the LT4. It almost reminded me of a reverse split style cam. I used to run one in my LS2 and despite the negative commentary I got from people saying it wouldn't work for an NA application, it actually did, and quite well at that. I think at the time I was making around 450 RWHP with it compared to the OEM 330 with supporting mods and torque output on it was immensely higher than anything stock ever was which is what I liked.. It's almost like a cam created exhaust scavenging effect.

With saying that, I can't actually say whether or not it would be ideal to blend the LT1/4 cam specs together and that would make for a great performing one without actually testing it out. I think at the time BTR or GPI did recommend me a cam with a 220/223 .612/.615 custom spec or something like that, but I decided against it because of compatibility with the OE calibration and what it would do to drivability if I ever had to revert back. Based on specs alone you would think more is always better, but that is not the case with these engines when you PD them. It's been proven out many times by other folks running these big massive spec'ed shafts and not getting results out of them compared to their counterparts running smaller profiles and getting awesome performers out of them.

So yeah, my answer, is ultimately inconclusive, because if I was to do it again and try a custom spec that blends the two together I would probably wind up with something I don't like because I use my Z as a streeter, but there is always a chance that it may perform great. I think especially GM has been doing this for so long at this point that the grinds that they spec out are pretty on the money and efficient for their intended targets.

What kind of gains are you attributing to the LT1's increased intake duration and lift? We're not talking about large cams here, as ZL14EVA posted his LS9 OE spec cam picked up 4 mph in the 1/4. I don't think you'd see a drivability difference with the stock duration the car came with from the factory. The LS2 being naturally aspirated is a different animal. These boost applications need help getting the extra exhaust out of the cylinder as there's a hell of a lot more to move than an NA car.

Here's a dyno of a FBO X Port ZL1 with the stock cam but meth as it doesn't have the lobe for the fuel system. I don't think the stock LT4 cam is the limiting factor but fueling sure is.

My argument here is if OP is going to put a cam in for more fuel (and power) but wants stock drivability and reliability, there are limitless better options than a stock LT1 cam spec. The whole goal is more horsepower, why not make it more efficiently in the process?