Good evening everyone, I have been doing a lot reading on this site & you guys are great. This is my first post. I have a 1987 chevy truck with a 350 TBI. I would like some advice on the plans that I have for it. I don't want nothing too extreme, just a little more stout than what it is. Here it goes. The engine is a rebuilt Jasper that runs pretty damn good, I already have Edelbrock Headers (shorties), Magnaflow Muffler 10 bolt posi rear end with 3:73 gears .Here is what I thought about:

Edelbrock performer tbi intake #3704
Stock TBI with 454 injectors
87-92 TPI fuel pumps in each tank (my truck has two tanks)
Dart Iron Eagle Heads, Cast iron 165cc ports 67cc chambers #1002436A
Comp Cam Xtreme Energy Hydraulic Flat Tappet camshaft Advertised Duration 262/270, Lift .464/.470
Custom Chip by either Fastchip (Ed Wright) or TBI Chips (Brian) who do u guys prefer..

Thanks guys for all your inputs, I didn't want to really get the xtreme tbi and then have to bore the intake to match, but let me know what you think. I may possibly put the NOS Truck TBI system on it as well. It will be later on down the line. My transmission will be rebuilt, 700R4 with shift kit and a 2000 stall converter or should it be higher like a 2200. Again thanks guys..

 

I would Say that it sounds like a solid plan. You dont have to go to a dedicated TBI intake though. You can get and adapter plate for any Carb style intake that way you will have room for the larger Tbi in the future. I would suggest that you get into prom tuning youself, It will be almost as cheap as getting an custom chip burned for you everytime you do an upgrade.You may also beable to keep your small block injectors and just increase the pressure. This will give you the necassary flow for more HP and you wont have to worry to much about your idle fueling. Just my thoughts. What type of HP are you looking for? Or expecting??

 

I was thinking about or close to 300hp if at all possible. Do you have any part # 's for adapter plate and or intake suggestions. Also it wouldn't affect the linkage would it. thanks for the suggestions and please keep them coming.

 

Anymore advice guys????? Thanks

 

twoodson

You have a good plan, but there are couple of things you should consider.

TPI pumps in each tank are somewhat of a problem. Commonly available fuel tank select switches from Pollack (all others OEM from Pollack - Niehof, AC-Delco, Borg Warner) do not take well to inlet port pressure. These units are made out of plastic and a good TPI pump is capable of 40+PSI. Over time plastic will crack under fuel pressure. Not a good scenario. These fuel transfer switches should be used in 'suck' as apposed to 'push' through configuration. Alternatively, if you find a heavy duty marine (metal) units you are good to go. BTW, you'll need two, one for supply and one for return, or a combination six port unit.

Camshaft selection is critical for TBI, SD system compatibility. What is the LSA on that Comp Cam Xtreme Energy? Do you have full specs for that cam? For stock SD system to be happy it needs about 16 to 19 in-Hg at idle. Large overlap cams will play havoc with O2 readings at idle. Volumetric efficiency of your combination will be different from any stock combination. Mail order tunes do not work, let me say that again - they are at best an educated guess. All of the above can be addressed with extensive tunning, but do you have time and money for tuning equipment?? For SD system - flash based EBL equipped C3 ECM or a later P4 with WBO will do the trick.

//RF

 

RF Master, thank you so much, this is the type of info I need because i don't want to buy a bunch of stuff and then be out of luck. I spoke with Brian at TBIchips and he suggested that cam along with a 50mm 350 TBI from xtremefi and also have my intake bored to 50mm to match it. U are correct, I don't have the $$$$ for the software. I apolgize but I am lost when you mention "For SD system - flash based EBL equipped C3 ECM or a later P4 with WBO will do the trick" What does the "SD" mean? There will not be anymore upgrades on this so those two guys were the only ones that I read good things about on mail order chips. I just want to know, who would you guys choose. Here are the cam specs:
Part Number:CCA-12-262-4Cam Style:Hydraulic flat tappetBasic Operating RPM Range:1,500-5,500Intake Duration at 050 inch Lift:218Exhaust Duration at 050 inch Lift:224Duration at 050 inch Lift:218 int./224 exh.Advertised Intake Duration:262Advertised Exhaust Duration:270Advertised Duration:262 int./270 exh.Intake Valve Lift with Factory Rocker Arm Ratio:0.464 in.Exhaust Valve Lift with Factory Rocker Arm Ratio:0.470 in.Valve Lift with Factory Rocker Arm Ratio:0.464 int./0.470 exh. liftLobe Separation (degrees):114Intake Valve Lash:0.000 in.Exhaust Valve Lash:0.000 in.Computer Controlled Compatible:Yes

Let me know what you think and everybody keep the suggestions coming.

 

Also RF those were the fuel pumps suggested by Brian. My truck has two tanks.

 

twoodson

I think I threw too much lingo at you at once. Lets take this a bit slow. Your truck (I am only guessing) is tipping scales at 5000+ lb dry. Add driver, fuel, etc you are around 5500 pounds easy. You have 700R4 and 3:73 gear in your rig which can make this ride a quick one of the line. If you look at my signature you'll quickly recognise that I have square body and it is '75 C20 with dual tanks! I have converted it from carburetor to SD TBI last summer. This conversion was made possible because of information found here on TGO.
Since this is TBI forum there are many members that love to experiment with TBI systems. There are some wild non TGO rides here, but the same tricks and techniques can be equally applied to third gens. So let see. Yes, about abbreviations:

SD - speed density - this what your truck has now to determine engine load. This system is found on all 1987 to 1994 trucks and uses MAP sensor (manifold absolute pressure) to calculate fuel requirements (plus other sensor inputs).

C3 ECM - this what you have - 1227747 truck ECM.

EBL - Embedded Lockers - a special retrofit board that basicly converts docile C3 ECM into a highly adaptable ECM.

WBO - wide band oxygen sensor - useful for performance tuning.

P4 ECM - later, high speed ECM found in OBD-1 94 to 95 and OBD-2 cars and trucks. Too much information - I have read some of it, lots of possibilities, greater adjustability. Do a search.

The 262 cam is OK for SD system. It has 114 degree LSA so it will probably have adequate idle vacuum.

Personally I would stay away from bored out TB's. Instead I would find 454 on JY and use it instead. Boring SBC TB (46mm to 52mm) is problematic for idle circuits. Instead of TB specific intake I would find a nice dual plane and an adaptor plate that matches your TB bore size to mount. TB specific manifold will require minor enlargement of the inlet plenum, where as carb intake does not. There are yeas and nays for either approach - so chose wisely.

Fuel tanks. I run a surge tank system. To put it mildly I have two inter twined fuel systems. I have low pressure lift pump that sucks fuel from either tank into small ( about 1 liter ) tank - excess overflow fuel gets returned back to a source tank. Meanwhile, a second high pressure Fuel Pump takes fuel from surge tank and delivers to TB, return line dumps back into surge tank. I do not have baffled main fuel tanks. To avoid fuel starvation during acceleration or braking surge tank supplies uninterpreted fuel supply to high pressure fuel pump. Fuel tank selection is done before low pressure fuel pump inlet - 'suck' though mode. Fuel tank selector never sees high fuel pressure. Pollack specifically states that is not intended for operation above 6 PSI.

//RF