I have a 1990 454SS pickup. For those unfamiliar with the 90’s SS they are TBI boat anchors, 230 hp with 385 tq at 1600 rpm. The ECM is stoneage! They have what are referred to as peanut port heads suited for a mild performance small block! It has a fresh rebuild with; forged piston, Edelbrock TBI cam, intake and headers. It has large oval port GM 781 heads (8.9 CR) roller rockers, 3” dual exhaust and full MSD ignition.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

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We put about 50-75 miles on the rebuild to sort things out, I had the 600 hp 496 (with a carb) that I built for my old Vette in it for a year. It sorted out pretty easy and ran pretty good, of course not like the 496! Guys with similar setups are getting 300-340 hp and 425-450 tq at the wheels. We then bolted on a Vortech V1-S trim kit, it was NOS (new old stock) I had picked up 2 years ago.<o:p></o:p>

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This also went off fairly easy. I went with a Warbro 255 in tank pump and dropped the Vortech booster pump. The Vortech made a big difference and I’m fairly pleased thus far! It’s making right at 5 psi boost, which is about what we expected with the mods. I do have a few problems. First is belt slip, surprise! I have ordered a custom 8.5”crank pulley (7.5” stock). I’m planning to use a 3.12” SC pulley. I’m hoping this will reduce belt slip and provide a pound or so more boost. This will increase compressor speed by 2000 rpm to 46,920 rpm at my 5,000 rpm engine rev limit. Shifts will be at 4,700 4,800 rpm. Is this too much?<o:p></o:p>

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I’m also getting fuel blow by at the TBI shafts. I think this is only happening during deceleration, the TBI is not worn! I tried a LARGE Mondo by pass valve but it seemed slow to close and delayed boost. I’m planning to add a second stock Bosch by pass valve to the inlet pipe to the TBI bonnet close to the compressor. ?? <o:p></o:p>

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I’m new at this, so all suggestions welcome!<o:p></o:p>

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Al (454SS/SC)<o:p></o:p>