Good morning. I purchased a ported l92 intake from peak performance. It was the radical ported l92. Since i installed. I noticed that the csm lope is much more notical thn before.light throttle is great but with parkin manuvers may stall. Part to 1/2 throttle is alil soggy up till maybe 3600 then the power is broad till like 65-6600. The runner lenght looks to remain the same but be opened up as well as the plenum and smoothed. I know a tune is needed but is this the effect of the extra volume.

 

Well a tune will solve most your driveablity problems . As far as the power curve you describe is accurate and will not change, it will be soft down low and 3600 is where everything changes in hp and tq all the way out. This is the trade off of radical port .vs stock or a milder porting job. The power is moved higher in the band. Removing the secondary plenum drasticlly effects part throttle and down low response.