Please look at the bottom of page where it says FINALLY about ignition system.
When looking at crate engines on line be sure to ask if their engine power numbers are SAE GROSS or SAE NET. A lot of engine builders list engines as Sae gross power which is how factory rated motors prior to 1972. In 1972 car manufacturers switched to sae net numbers which is easily half the reason power numbers listed for vehicles in 1972 were dramatically less than 1971. The difference is sae gross is power engine makes with no accessories (not even water pump), no air filter and no exhaust off their very large long tune headers that would never fit in a vehicle and no exhaust. Sae net is power at flywheel with all those components on engine as it would be in vehicle. This typically yields a number about 20-25% lower than those gross numbers. Multiply their advertised number by .75 and it’s much closer to what I estimate power at in the vehicle. Very misleading in my opinion. A 180hp 350 tbi motor makes a good 230-240hp using Sae gross math. Very few places advertise Sae net numbers. SAE NET numbers are what I will give you when calculating engine power from the specs provided so make sure you also look at the build of any engine online your looking at. if they are promising 300hp or more and using TBI 350 heads then they are either just lying or using SAE GROSS which you can never replicate in a vehicle.
These are 3 TBI Compatible recommendations I have for small block Chevy engines. good performing reliable setups that won’t break the bank to bad and are good fuel efficient designs as well. I have decided to add a couple big block engines on this list as many of you especially 4×4 truck owners should consider a good big block as they make more power at lower rpms and so not as necessary to regear for your larger tires as too many 4×4’s out there running poor gearing for the size tire they are running. Then also lots of 1 ton trucks with wimpy 350 engines that really need big block or turbo diesel like torque.
- http://www.jegs.com/i/GM+Performance/809/12530282/10002/-1 (2bolt mains) http://www.jegs.com/i/GM+Performance/809/12530283/10002/-1 (4bolt mains) This option can make 300hp an 350lbs of torque with good exhaust and the TBI setup listed below option 3.
- Take option 1 and replace the cam with http://www.summitracing.com/parts/lun-20080660 for 30hp and torque gain over option 1. or you can buy the engine from GM that way at a rather steep price premium. http://www.jegs.com/i/Chevrolet-Performance/809/19367080/10002/-1
- http://www.ebay.com/sch/6000/i.html?_nkw=vortec+383+tbi&_dmpt=Motors_Car_Truck_Parts_Accessories&_rdc=2 360hp and at LEAST 420lbs of torque. If you prefer a different vendor for the engine http://www.summitracing.com/parts/mll-bp38303ct which is nearly identical motor. Blueprint just did their dyno testing with more restrictive stock throttle body and such. has the same 360hp 420lb potential.
- I get requests from customers for something cheap that is a little better than stock motor. This is what I came up with. http://www.jegs.com/p/Chevrolet-Performance/GM-Goodwrench-350ci-260HP-Engine-Packages/752506/10002/-1 While 260hp is dreaming the 195hp is the more realistic number. the heads on this engine are essentially TBI heads with altered intake bolt pattern and a level 3 camshaft which will yield 15hp over stock TBI cam. combined with the stage 2 level 3 chip though that motor should make around 210hp and 300-320lbs of torque for only $1500 shipped to you. The intake will need to be altered http://www.persh.org/pickup/TBI%20Intake%20Manifold.htm
vortec heads need http://www.jegs.com/i/GM+Performance/809/12496821/10002/-1 and bore it to match a 1990 454SS TBI gasket and use a bored 46mm 600cfm TBI unit from www.tbiparts.com and my CUSTOM CHIP, Which you can now order on the Ordering page on the menu of this site. Also you will need to either modify your stock throttle cable bracket or use Edelbrock 8032 throttle bracket. if you need to have EGR for emissions testing then you need EGR tube and headers or driverside exhaust manifold for a 1996 vortec truck.
Now if you dont need EGR for emissions testing then using an Edelbrock 2716 intake and open center TBI adapter from sprperformance.com will make 25hp more than the GMPP intake which seems to max out around 275hp.
SEE IGNITION NOTES AT BOTTOM OF THIS PAGE.
5. Big Block option 5. Since most big block customers are looking for torque for towing. The GM HT502 crate engine fits that bill to a T. http://www.jegs.com/p/Chevrolet-Performance/Chevrolet-Performance-502ci-377HP-512TQ-HT-Towing-Engine/760849/10002/-1 377hp by a LOW 4500 rpms and 512lb of tire shredding stump pulling torque. MUCH better engine than the stock 230hp/380tq TBI 454 engines. Requires a bored 54mm 750cfm TBI with 22lb of fuel pressure and bored edelbrock 3764 intake along with fuel pump upgrade and custom chip. If swapping from 350 then you need some accessory bracketry.
6. Option 6. GM ZZ454 for those that want a bit more horsepower and willing to give up just a little torque. http://www.jegs.com/i/Chevrolet-Performance/809/12498777/10002/-1?parentProductId=956498 440hp by 5200 rpms and 500lb of fun loving torque. We have a clone of this motor as Jims 454SS project under customers projects. Requires same larger throttle body and pressure as the HT502.
Performance is never cheap but putting options out there for GOOD RELIABLE TBI power options. If I am recommending engines that cost this kind of money then I try to recommend something that is going to run another 200k miles for you.
Looking for gas mileage improving modifications. Nothing will improve the gas mileage as much as having the motor in good tune with fresh plug wires, plugs, distributor cap and rotor button. In fact a new Pertronix Flamethrower coil D3002 from your favorite vendor will help throw a hotter spark across those spark plugs for a more complete burn of the fuel your using and thus better gas mileage. Also, I find that the stock AC Delco plugs gapped at .040″ works better than anything. A combination of all should give you respectable gas mileage from your vehicle which is very important these days. You should also consider ASP under drive pulleys as turning the accessories slower frees up HP which uses less gas. Good exhaust and air intake will help as well and lastly 5w-30 motor oil. Unless your motor leaks oil like no tomorrow use the factory recommended 5W-30 oil as the lighter oil is going to have less drag on the motor which may not sound like much but every hp we free up without internal modifications to the motor is FREE hp (which means it didn’t cost us any more fuel to make) and goes straight on down to the wheels which is the purpose of HP. Electric radiator fan conversion like all modern vehicles is also recommended for increasing the efficiency of whatever engine your running in your TBI vehicle.
Finally, if you spending this kind of money for a new engine. Don’t skimp out on the ignition system. Don’t go using your 200k mile stock distributor and don’t get the chinese crap off ebay or even your local auto parts store. Currently only recommending Recommended ignition setup: Distributor AC Delco 01104060 coil http://www.summitracing.com/parts/pnx-d3002/overview/ with Accel plug wires http://www.summitracing.com/parts/acc-5114k/ as they have a tough outer covering and good low resistance to get that spark energy to the plugs for a strong fire. For spark plugs AC Delco R44TS for 1/2″ reach TBI style heads or R44LTS for 3/4″ reach aluminum or vortec style heads and with this ignition configuration .040″ plug gap. Skimping on this stuff typically just winds up giving us both headaches trying to figure problems out. Most of your stock sensors will be just fine but if you do replace them USE AC DELCO replacements. I can get them through my local advance auto. Typically takes a couple days to come in and doesn’t cost that much more. PLEASE PLEASE don’t complicate TBI with MSD or any other ignition boxes. They do not work well with TBI and can possibly cause a LOT of issues. Best just to avoid that type upgrade altogether. I don’t like working on my stuff more than once for the same thing and doubt you do either so do it right the first time.