Yea so long story short I'm doing a vortec head swap on a 180k mile LO5 TBI truck engine. I had it all torn down by 10 AM (started at 6:30 AM) and got the heads back on after lunch. The sleeves looked really good for the most part. The few I could see seemed to have good cross hatching on the front and back of the sleeves but of course the side was smooth and a few very light vertical lines but no scoring of any kind. Also I swear my engine has the same flat tops as a L31 vortec 350. Fast355 told me they would be dished but these were flat, well maybe an 1/8 inch dish to them, and 4 valve reliefs per piston. Anyway the heads were used 906's treated to some porting done by me and were worked over given the same treatment a set of race heads gets including three angle valve job, 22* back cuts on the intake valves, new seats, I supplied LT4 springs, retainers, keepers, and seals and so on. I've hit a few snags with the fuel lines (hard lines have gotta go, at least sectioned out and fuel injection hose put in its place) and my 454 TBI to spread bore carb adapters coolant outlet on the back is in direct line with my coil. Also have no idea where the EVAP purge soleniod is gonna go if I even reuse it, I'm thinking of remote mounting the MAP if possible, and the throttle cable bracket will need engineered to reach the nose bleed high TBI. From the valley to the top of the TBI is over 6 inches. Anyway so far so good but it won't get done this weekend which kinda sucks but its been a good learning experience anyway. Almost forgot, I'm using Felpro metal shim .015 thick head gaskets and felpro 1255 paper vortec intake gaskets coated with 2B permatex on both sides for what I hope to be a perfect seal. Desktop dyno shows this setup to be making around 345 hp at 6k rpm and 419 ft lbs at 3000 rpm. Should be interesting when I get it done. Sorry no pics of anything but I might take some of it with the new topend on just so you can see what kind of creation I've got going.

 

What cam will you be using in this setup? Even with a mild cam, the vortecs make good power on a street engine. Also, it does sound like you have dished pistons. Theyre not bathtubs like some, but like other stock pistons, they have a slight dish with 4 valve reliefs. My 350 has that same style of piston.

 

I don't remember the grind number but its equivilant of an RV cam. It should make 415 ft lbs at 2k rpms and not drop below 400 ft lbs until 4000 rpm and still make respectable hp.

 

oldred95 welcome to TGO...
Its alot more useful here for TBI help... the guys here will help you well...

Im having the same problem, throttle bracket and ignition coil bracket fabrication... Ill have some pics as I work this out later today.

 

Got it mostly all back together today, just a bunch of loose ends to finish up. I modded the stock throttle cable bracket and am going to use some pipe spacers to get it to the right heighth and for valve cover clearance. I'm considering not even running an EVAP purge solenoid to eliminate clutter. I need to fab a new MAP bracket still and finish plumbing the coolant and fuel lines. Also I just checked the pistons out of the vortec 350 block and they are the exact same pistons in my trucks engine. And for anyone that cares, check your coil wire on the coil end for corrosion and or electrolysis buildup. Mine was caked with crap and I'm not real sure how it was even making contact. Might be an easy quick fix or good for a little mileage.

 

Thats pretty much essentially my engine. I dont think it quite makes as much as DD predicts, but around 370 ft-lbs with around 285 HP at the crank seem reasonable once its in the truck with all accessories installed. In a car it makes for a real fun to drive setup. Not the fastest thing out there, but its got enough power to mess with mustangs and stuff like that. In the truck, it should provide ample torque and power for towing and around town driving.