Hope someone can help me with this.  I have a 95 chevy 1/2 z71 350 ci. TBI. Without going internal, and to gain more hp and torque, I have installed Ederbrock Multi Point EFI system, Accel ingition, Gibson Headers, KN high performance air intake kit, Flex A Lite dual electric fans,and Flowmaster dual exhaust.  The only thing, I think I have left to install is a electric water pump to finish off external modifications.  Is there anything else I can do without to gain HP without going internal.  Supercharger??

or

I would rather sell the current engine and if I could put a  High Performance crate engine like the ZZ4 in the truck but all the engines,( with the exception of some 383 strokers that use the TPI manifold)  are not for the 95 chevy truck due to the emissions/computer.  I want a engine with 4 barrel and not  the 2 barrel TPI which came with the truck.

Thanks

Steve

95 is one of those cross over years which happened a lot since the mid 1980s. 95 in particular is the cross over in trucks from the swirl port engines to the 96 Vortec engines which then continues to the end of SBC I production in 2002 for trucks.

If you have and early model 95 engine it's pure Swirl-Port. If it's late 95 production it's probably a mix, most often consisting of an "880" (last three of cast numbers) Vortec block with Swirl-Port heads perhaps even a head that seems to mix some Vortec chambers and ports that bolt up to TBI.

If you have an 880 block, it is prepped for a factory roller cam and may have one in it. The only way to easily tell is to pull a push rod, if it's about a half inch shorter than a stock flat tappet push rod chances are really high that there's a roller lifter down in the valley.

It's somewhat unfortunate that you made all these external changes with out going inside a bit, especially where the EFI is concerned as you really need to go in and fix the heads and the cam at a minimum to get any real power out of this motor. That however requires a chip with programming that understands what you did because the need for a cam with more timing lowers engine vacuum throughout the operating range and that throws the sensor readings off against engine RPM and throttle opening so the chip becomes unable to match the engine's fuel requirements with the sensory data it's receiving. Thus the need for new programming which corrects this mismatch.

The trucks came with really weak cam timing, something on the order of 180 some degrees on the intake and 190 on the exhaust, with mighty little overlap, early intake closing, and lift well under .4 inch. These engines were optimistically rated at 207 hp on the crank. The swirl port heads choke off anything that looks like high speed airflow into the valve, but the injection is turned off by the computer at 99.5 mph anyway, so without a chip that lets the speed up higher you can't use more top end breathing capacity anyway. The heads really need to be replaced as well as the cam. Your Edlebrock conversion will require you look to the after market rather than factory Vortecs as the Vortecs won't bolt to you existing intake. But there are lots of choices starting with Edlebrock Performers, DART, World; Comp Cams sells heads, Holley and many others that do bolt to your intake.

I think you started at the wrong end of the equation except for the headers and the Edlebrock MPEFI. The rest of this stuff is eye candy; it doesn't make any power and costs a lot of money, money much better spent on a cam, perhaps 1.6 rockers, and cylinder heads. For the money you've sunk in electric fans, electric water pumps, K&N air filter, Accel ignition, you cold have built a lot of power (I'd say about 330) instead of recovering a few ponies otherwise lost to the parasitic drag of engine utilities. Where the Accel ignition is concerned you can't even get that motor into an RPM range where it needs the stability of the Accel over stock HEI. The K&N filter is a lot of money that mostly just lets dirt into the engine. It's mighty hard to beat the stock air-cleaner with it's cold air connection to the outside world. Air sourced from out side instead of under the hood is worth a 1% power gain for every 10 degree temperature reduction. Once again, you can't turn this engine tight enough to take advantage of the K&N's top rated air flow, and remember you get dirt with that flow.

You can't put a supercharger on without also making extensive internal mods to take advantage of it and strengthen the motor so it can survive it. Again this takes a major mod to the injection's computer.

You can build a ZZ4 type engine with a cooler cam say not to exceed 220 degrees measured from .050 inch, with a lift under .5 inch and an LSA around 115 degrees or more and still creep by emissions with your existing induction. Problem with the 95 is it's kind of an orphan but you can work around it and remain emissions legal. If you live in a state that does a technical inspection as well as tail pipe emissions like California, you can't use Vortec heads on pre Vortec engines because GM never saw fit to qualify them for older engines, but there's lots of aftermarket people who make equal to, or better heads that did qual. them.

Holley offers a 4 bbl TBI that with a proper chip programming change could be adapted. However, the custom chip houses stopped making programming available for these when used with a stock computer. But all is not lost. What you'll eventually need if you do internal mods or put in a 383 kit is more air and it turns out that GM makes a 670 CFM TBI that's used on the 454, Holley makes a 670 CFM replacement TBI (502-7), while not listed for this application does work on it. Outfits like Turbo City can take your existing TBI and bore it to 2 inches, which nets, yeah you guessed it, 670 CFM. Given that all you want out of the TBI is a place to mount throttles, sensors, and the air cleaner either getting a 454 unit out of a wrecking yard or having Turbo City mod your existing unit is the better way to go than spending 400 bucks for the Holley and throwing half of it away since you will not need its injectors or pressure regulator.

If you think I think you threw a lot of money away on stuff that’s over advertised and under performs, you’re right. I’m sorry; it’s a tough lesson we all have been through.

Bogie

Thanks Bogie, Yea I messed up and read all the hype that is printed in Summit and Jeg's catalogs.  The engine in this truck only has about 500 miles on it.  The original blew a rod at 48K miles. Bad oil pump.  I was in a hurry and needed my truck for work so I bought a crate 350 and dropped it in.  I am really dissapointed that the 95 model is not flexiable. I'm a older guy and retiring in a year and I'll have time to work on the truck.  I live in Pa and they have emissions.  My truck has never been check for emissions as it does not go over 5000 miles per year so I am not concerned about emissions checking.  I baby it I guess.  As you have a lot of knowledge about engines, I would just like to get a crate engine, and drop it in without that emission stuff.  I assume that  those engines don 't need emissions and if so, I need to know where to start.  Are there any type of books out there that can give me information as to swaping a emission- computer engine with a non emission-computer engine.  Since I was 13, I told myself that I would build up a  High performance auto/truck when retired and as the time is coming and I can now afford it. (kids are grown and gone)

This guy  really appreciates all the information you provided me.  Sorry if this email is too long.

Thank you!

Steve

Steve, I hear you on the being old thing myself, I'm few years past being able to retire and just can't seem to leave my day time job at Boeing. My wife is quite a bit younger than me and has 5 years to go to 55 where she could take early retirement. She works at home where my project's noise and paint smells don't really get along with her. So when we pull the plug, we're going to move to where I can have a shop that isn't below the house and not a house in the middle of a major city with neighbors that complain to the SMOG police every time the smell of urethane escapes.

I've been hot rodding for a long, long time having grown up in San Diego in the late 1940s thru 50's right in the middle of all that founding of modern hot rodding so I'm unable and unwilling to out grow it.

The problem with changing an emissions qualified vehicle to a non-emissions vehicle is that it's illegal whether your city, county or state checks or not. And I try to be a good citizen about this stuff since we all breathe this air. You guys in the eastern states have seen the damage of acid rain from the fall out of factories and power stations west of you, I've lived in San Diego, LA, San Bernardino, DC, Atlanta, Houston, Boston, Cleveland, Seattle, Salt Lake, Dallas/Ft. Worth and have seen the icky pollution in those places, so anything we can do to clean up the neighbor hood is good in my opinion.

Modern electronically controlled engines are a quantum improvement over anything that went before. They make very good power and get very good mileage and really cut down pollutants and last much longer than engines that predate them. The idea of getting a couple hundred thousand miles on an engine back in the days of leaded fuels and carburetors was beyond imagination, just getting one of those critters to a 100 K was an achievement resulting from frequent oil changes, monthly tune-ups, and a top end rebuild every 30 to 40 thousand miles to get the lead out and replace cooked valves. Unleaded fuel and electronic fuel injection/timing has made a wonder of difference.

I certainly don't know what crate motor you dropped in the truck, but there's much you can do that will make improvements. Cold air is good for power and you can source that from behind the grill. But in PA you'll need some heat in the winter when the engine is cold so the hot air stove off the exhaust into the air cleaner's intake is good to retain, but you need to make sure it's only open when the engine is cold. The 95 has a heat exchanger in the radiator for engine oil, this helps the engine warm up faster which is a good thing to reduce wear and tear. Start up and warm up is where most wear happens so the faster you can get thru that phase the better.

What this engine has for a cam I don't know, if this is a good national brand  engine given the part number I can run that down. Inside this could be a roller or a flat tappet cam who knows at this point. Up in the heads it could have guided or unguided rockers, a simple switch from stock 1.5 ratio to a 1.6 ratio especially if the new ones are a roller rocker will net more power by about 10 percent with no other changes. But you need to know whether or not it has self guiding rockers before ordering parts.

Heads, again don't know what's on the engine, if not Vortecs, they're possibly swirl ports or some other earlier large chamber SMOG head with anemic compression. Heads are kind of expensive but modern emissions heads have gone back to Ricardo Fast Burn chambers and better port shapes. GM makes 3 different styles of Vortec, the original and two newer versions which unlike the original Vortec will accept intakes such as you have. While this stuff isn't glitzy, these heads are good for at least 40 horses or more by just bolting them on. You get better fuel mileage, more power and lower emissions, what a deal! And if you shop E-bay, it's possible to score some real bargains on this stuff. Just don't get LT-1 or LT-4 heads as reworking their cooling to a standard GEN I engine is really difficult. L-98's are rather the first cut from the factory at a modern high performance head. While better in their day than what came before them their quite obsolete by today’s standards.

Cam, again not knowing what motor you bought, who knows what the cam is. But whether flat tappet or roller, there's lots of replacement choices. Getting up to about 220 degrees of duration with about a half inch lift would add 60 to 80 hp against the stock cam if this is a stock replacement engine and such a cam will be compatible with your injection.

The injection could use a bigger throttle body, like I said before, this is easily solved with a 454 unit off E-bay or from the local wrecker. The stock 95 TBI is about 450 cfm capacity which is barely enough. If you really want a 4 barrel, a carb could be used for its throttle body and brackets made to adapt the MPEFI’s sensors. Somebody makes a 4 barrel throttle body for this application; I’ll check that out I don’t have the name on the tip of my tongue

Compression, given this a stock replacement engine, it probably has large chambered heads and dished pistons with a compression of about 8 to 1. For any kind of a cam over 190 degrees of duration at .050 lift this won't work. As the cam gets longer the compression needs to get higher. Fortunately new heads with chambers of 50 something to 60 something cubic centimeters (ccs) go a long way toward solving the compression problem without having to replace pistons.

There are a lot of really good books out there and I'll take this week end to get a reading list together. Just remember that building engines is a lot like going to Vegas, you start reading about all this neat stuff and drift off dreaming about what ifs, you get greedy and before you know it your eyes glaze over and what common sense you have slips away in a golden haze of flaming burn outs and the other guy gazing at your tail lights or a bunch of geezers standing around getting aroused looking at your chromed drive shaft. Jezzze will Viagra do that for me? Pretty soon you’ll need shock therapy, which you’ll get when your wife sees the VISA bill at months end.

Bogie

Hey Bogie, when you decide to move, I would love to have ya as my next door neighbor.  Just imagine, all that knowledge at my disposal, sure would be nice.  I would wake you up in da morning with your hot coffee and a set of big block heads ready to port.  My wife would think I was having an affair, from staying out late.....

ET 406

I have the same issue with my wife, she thinks I keep another woman in the garage, otherwise why would I spend so much time there.

Bogie