I'm ready to order a few parts and get the exhaust installed on my '60 suburban with the above engine. It's got an Eddy 4 Barrel, an ISKY 270/280 Cam and some other mods done. Machinist said it's probably a 330ish HP engine. In any case, currently I'm running one 2" Ram Horn Manifold and one 2" truck manifold through a 2" exhaust pipe. The mufflers are I think just basic 5" round about 15" long mufflers and then tailpipe out the rear corners after the wheels. The mufflers are rusted out, so it has some obvious sound to it, which everyone seems to like, including myself. That said, it is time to even things up on the Manifold/Header front and take care of the leaky mufflers. I've been trying to listen to YouTube sound bits of different mufflers and setups, but obviously it gets confusing and tough as it's actually kind of tough to get the same camera angle/sound and the same engine type/setup. That said I had sort of decided I liked the Borla XR1 Sportsman, but they are a bit pricy(though doable), but the shops seem to try to steer away from them as they are a 3" outlet & inlet and thus makes tucking them up under my truck more tricky as it's lowered 5" in rear with coils in the trailing arm suspension. Up front I have 2-1/2" drop spindles then torsions cranked down another 2-3" to give it the hot rod rake look. One shop suggests more of the Flowmaster 40 series as I had a set on a 1999 K1500 Suburban with 5.7l vortec and I liked the sound of it. The other shop recommends the Magnaflow Mufflers and said he's had great luck fitting their 5x8x14 mufflers under this X Frame. He doesn't think the round Borla will fit, but as I said my current leaky mufflers are 5" round. They both say 2-1/2" is going to be tricky and thus suggest 2-1/4" pipe at the biggest. The one said nothing wrong with my current 2" pipe, just new mufflers and tail pipes, BUT as I said the mani's aren't matched. Through talk online with this era truck forums headers seem to be very tricky with this suspension and frame, almost everyone suggested the 2-1/2" ram horn mani's, but Summit says Sanderson makes a Shorty that should fit great and has excellent reviews. Cost is about $150-175 for the Ceramic coated Ram Horns, about $325-350 for the bare steel Sandersons and over $500 for the ceramic coated. Cost is always a consideration, but I will do whatever is best as I don't want a regret and at end of day a few hundred more isn't the end of the world for me. That said, I don't want to throw my money away either. The truck is purely street use, I won't take to strip and am not a street racer either. I just want a nice sounding (I do like some throaty old school hot rod sound). I also want to hear the cam lope, etc... Truth is what I've heard on all 3 mufflers they all sound really good. I guess my question is, am I holding the engine back noticeably with the Ram Horns over Shorty's, what about 2-1/4" vs 2-1/2" pipe? I'm guessing any of those mufflers will perform well. Do I just stick with the mani's I have, keep the 2" pipe, keep 3bills plus in my wallet and just swap out the mufflers? I'm also thinking I want an H pipe and tests do seem to show they help low end. The one shop said they quiet things down though....I heard they add more of a low rumble....is that just the engine sounds coming though more? In any case, anything is helpful. If the magnaflow's are just as good as the FlowMaster and Borla, they seem less expensive and reviews seem excellent. With the Magnoflow's I was quoted about $600 for the complete exhaust Manifold back. Obviously they H pipe will add about $100. If I go with the Headers and the Borla's I'm over double the cost and wondering if that's anything I'd ever notice.