TBICHIPS.COM BBC 454 page

I will be honest here.  I always wanted a 454SS but never could justify the $$ for the performance you got for a stock SS.  Plus I would want the 91+ 4spd automatic so I could have some gas mileage anyway and they are lot more rare than the 1990 model.

Here are the summit racing air filters that I use and recommend.

SUM-239421 14 in. diameter, chrome, flat base, 2in. element, air cleaner assembly for tight clearance hoods

SUM-239431 14 in. diameter, chrome, flat base, 3in. element, air cleaner assembly

SUM-239441 14 in. diameter, chrome, flat base, 4in. element, air cleaner assembly

Like the small block V8 the heads are the biggest power limiting factor.  I can't really recommend what heads to use since you have that whole block generation thing going on especially between the 90 to 91 trucks and oval port and rectangle port thing.   Stock heads are iron and flow terrible.  So being iron, porting is expensive and time consuming and thus not the recommended method.  What I can offer is the larger the intake runner is in CC the higher the rpm powerband will be to create the velocity through that runner to make power.  So for torque get as much flow as you can in the smallest intake runner as possible.

Throttle Body: If you change the heads the stock throttle body is not going to flow enough air for the heads.  Contact www.rvmorsemachine.com  and get them to bore your throttle body out and also pickup a 255ltr in tank pump as stocker is not going to cut it either.

On the heads, the stock TBI peanut port heads are just plain awful but some porting and larger valves can at least make them tolerable.  There is a reason the stock TBI 454 only made 250hp at its best from GM and this is the key reason.  You can make about 320hp with all the other upgrades but to get real 454 power your going to have to change the heads. Good bang for the buck for the Mark IV blocks is the 049 GM 454 oval port head castings, with some larger valves and a little porting you can make in the 450hp range.  Mark V your kind of on your own.  Some use the Vortec 454 heads but haven't seen any dyno numbers or flow numbers from them yet.

1st cam I recommend is the GM Performance 454SS Hot cam GM part number 12361316. well it was the recommended cam but GM discontinued it.  Lunati makes a similar cam which I will list next. but the GMPP hot cam specs are:

Advertised duration 210/218 and lift is 485/490 with the lobe separation at 115.   If you plan on towing heavy loads or have a heavy duty 3/4 ton + truck this should be a very nice cam for you.  It will also make a nice little cam for a mild 454SS build.

New first recommend cam for the heavier duty trucks is Lunati  90454LK

Specs: duration @ .050 210/218 with gross lift .485"/.502" on a 114 LSA which is a tad better cam than the GMPP hot cam.  Very streetable and will pretty much sound stock and just run more like what GM should have put in the things.

Well the Summit SUM-1300 cam $55 with no lifters ( I don't recommend the Summit Lifters, use a good lifter) and  doesn't look too bad for you guys that tow a lot and want low end torque to pull those heavy trucks around.

Specs: duration 208/218 and the lift is .475/.500 with the lobe separation at 112 which is on the very bottom end for TBI.  But the 1500-4000 rpm powerband will appeal to the torque lovers and that lift will make good power. 

The SUM-1301 is in between the 2 GM cams.

Specs: duration 218/228 and the lift is .500/.500 with a lobe separation of 114.   Powerband is 2200-4500.

If you don't want to run a Summit brand cam then Edelbrock 2162 has the EXACT same specs as the K1301 cam and is a GREAT cam in 454 trucks.

The SUM-1302 is duration 228/238 and the lift is .540/.540 with a lobe separation of 114 degrees.   Summit advertises the powerband at 2500-5500 instead of GM's 2200-5700 but the specs are the same.

When building your 454 for TBI, you need to consider the following.  The injectors are only going to be able to make about 450hp max and that is with a pretty hefty increase in the fuel pressure area.  However, the stock fuel pump is only good for a little over 300hp.  I recommend a FPG001 from www.apeusa.com if your planning a project to make more then 300hp. Next the stock 454 TBI only going to flow around 600 CFM of air so once you reach 4000 rpms or less depending on the heads and cam you use that 454 is going to start running out of air and it will be like the restrictor plates that NASCAR uses on the super speedways to cut their power back.  Increasing engine displacement like the 502+ BBC's will only make that problem worse.  More cubes = more air.   So if your going to run big heads and big cam its very likely that you will end up using a CARB to get the power that motor is capable of.

For you guys looking to make big power with your 454's and stay fuel injected check out the 4bbl TBI unit from http://www.auto-nomics.com/cgi-bin/showresults?a=detail&part=12168-001 with IAC option and this unit uses 4 high impedance TPI style injectors which the TBI computer can still run.  The TBI computer can fire 2 low impedance TBI injectors or 4 high impedance TPI injectors and those high impedance injectors can come in sizes up to a good 80lb/hr from www.racetronix.com which can support 600hp which will be a little hard to achieve with the cam limitations we have with TBI anyway.

Intakes.  Pretty much any carb intake will work on those trucks with the adapter that many of the 454 TBI trucks came with from the factory.  Chose an intake that has ports to match the heads your using and is designed for the powerband of the cam you want to use.  Anything aftermarket will flow better than stock.

Exhaust.  Anything will help the sound of that beasty 454 but you have a few options.  You can use shorty headers that were designed for the TBI trucks and mate to a factory like exhaust setup.  Any brand should do.  The HP differences aren't that great.  Remember the larger the individual tube size the higher the powerband it will work with.  Smaller tube size = better low end torque.   However most of you that talk with me about your chip are running true dual exhaust which if fine just keep this in mind.  If your going to run true duals, do it with long tube headers.  These usually don't have a place for a O2 sensor but the bung can be welded in.  The problem with long tube headers is when you mount that O2 sensor way down in that collector the exhaust will not heat it up like the shortys.  Use a 95+ S10 4.3 3-wire heated O2 sensor and use the dark wire for the computer and hook one of the other wires to a ground and the other to a switched hot (we don't want you to run the battery down).  This will give you the most power from a true dual setup.   Catalytic converter(s).  We like to stay "Green" around here so Cats should be used.  I recommend the Carsound cats that you can get on ebay all day long for around $60 each.  They flow great (real close to $250 Random technology cats) and really won't cut back any of your hp and at that cost, lets do our part in saving the environment.  Even if you are driving a truck that gets 12mpg. 

ANY SUGGESTIONS OR RECOMMENDATIONS WOULD BE APPRECIATED.  sales@tbichips.com