73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Unofficial on July 13, 2008, 11:05:33 pm
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I've had a 350 in the shop for a while getting rebuilt, everything is done. I got it bored out, the heads are rebuild, the crank is ground, and the whole bottom end is put together. Now I need to order parts. I already ordered the cam, gaskets, and an oil pump, but will I need anything else for the swap?
I currently have a 305 TBI with a 700R4 transmission, and I'll be swapping over to the bored out 350 TBI. I'm keeping the 700R4. I know that something has to be done to the computer. Is it a chip, or do I need to take in somewhere? I'm new to this...
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Get an oil pump driveshaft with a steel sleeve. Run a standard volume oil pump unless you plan on putting on a high capacity pan. Timing chain set? How are your tins? Intake manifold?
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Can I get an oil pump driveshaft that is made for a high volume pump and use it on a standard volume oil pump? Because I'm only seeing steel-sleeved driveshafts for the high volume pumps.
My timing chain set is good, but I forgot to ask, Will my stock 305 intake manifold fit onto the 350? Because the manifold that came with the 350 is for a carburetor.
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yes the intakes will swap.
http://store.summitracing.com/partdetail.asp?part=MEL%2DIS%2D55E&autoview=sku
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steel sleeved driveshaft will work on the stock pump, it is for replacing the plastic sleeved factory piece.
305 intake will fit any SBC. You need a chip burned based on your engine components. What cam did you go with, compression ratio/pistons... etc?
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steel sleeved driveshaft will work on the stock pump, it is for replacing the plastic sleeved factory piece.
305 intake will fit any SBC. You need a chip burned based on your engine components. What cam did you go with, compression ratio/pistons... etc?
This is the cam I'll be ordering: http://store.summitracing.com/partdetail.asp?part=SUM-K1102 (http://store.summitracing.com/partdetail.asp?part=SUM-K1102) Also, if it matters, the engine is bored .040 over.
I'm sorry, but I have no knowledge on this chip stuff, so any help here will be appreciated. :)
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You just need the prom from a 350 ECM or just pick up a used ECM for $30 and be done with it. The prom has the fuel map and look up tables burned into it. The tables are different for a 350 than a 305. Or buy this http://store.summitracing.com/partdetail.asp?autofilter=1&part=MVC%2D187121&N=700+4294914956+4294908216+4294925008+4294840140+4294908008+115&autoview=sku
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For your ecm, service number 1227747 was used in GM light duty trucks between 1987 and 1991 with engines 4.3L V6, 5L V8, 5.7L V8 and 7.4L V8 with automatic or manual transmissions. Since you already had the 5L, the ecm should be good to reuse. But like the guys say- you need a new chip burned because of the engine mods.
www.tbichips.com
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What about fuel injectors guys? Weren't the 305 injectors rated at 55 lb/hr whereas the 350 had either 61 or 68 lb/hr? Not sure about this Unofficial, wait for the others to chime in.
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Alright, a couple other things here.
I know about the injectors. The 305 injectors will work, the o2 sensor will eventually adjust the fuel input. The only thing the 305 injectors won't do is perform as well at top end, which isn't a bid deal. It's not like I'll be racing or something.
Also, is having a new chip installed absolutely necessary for the 350 to run? Because I thought the only thing the computer does is sense the fuel mixture with the o2 sensor, and then it sends information on how much more or less fuel to inject through the fuel injectors. I could be wrong, but if this is the case, then I'm not going to buy a new chip.
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You're right that's what it does, but only within certain parameters. A chip simply redefines those parameters based on displacement, cam, compression, increased head flow, so on, and so on. And plus that chip Vile showed you is cheap, why not go for it?
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You're right that's what it does, but only within certain parameters. A chip simply redefines those parameters based on displacement, cam, compression, increased head flow, so on, and so on. And plus that chip Vile showed you is cheap, why not go for it?
I know you guys probably don't care, but my dad was yelling, having a fit because I mentioned buying a chip for my truck. He started saying how I'm not building a high performance racer (which I'm not) and I don't need some chip to give me the best performance out of my engine. He also said that if I buy this chip, then I'm screwed because nobody will work on it when there's a problem because it's a modification that is "too complex" or "not factory." That's the difference between him and I. When he does something, he'll do the bare minimum to get it to work. When I do something, I get everything I need to make my "project" the best it can be, even if it means spending some extra money.
So by not installing the chip, will the motor run like crap? How about harming the motor?
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Probably won't run like crap, probably won't run its best; definitely won't hurt it. Wait for someone like Vile or Capt to look over this thread and give you more input, because I'm not a TBI pro. But I wouldn't be worried about nobody wanting to touch it after installing a chip. If the chip is determined to be the problem it's simple enough to remove and return to stock. And besides you'll be the one to work on it right if something goes wrong? Right? ;)
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The 305 and 350 use the same ECM, BUT they don't use the same chip or injectors from the factory. The chip has different tables that is predefined for certain parameters on both motors.
Can you run it like it is, yes.
If you want it to run the best, you at least need a chip for a 350 due to different fuel requirements of a larger displacement.
You can run 305 injectors, but I would recommend increasing the fuel pressure. You can run the 305 chip, but you won't be getting the most out of the motor.
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IMO, buy the chip, fix anything that goes wrong yourself, assuming any mechanic you talk to actually cares if its got a different chip in it..99.9% wont, only a stealership will care..
My first reaction was to say buy the chip and tell your dad to go stuff himself, but since you're 16 and i assume still living at home, that probably would NOT be advisable..
If you're buying it with your own money, why would he throw such a big fit about it?
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You're right that's what it does, but only within certain parameters. A chip simply redefines those parameters based on displacement, cam, compression, increased head flow, so on, and so on. And plus that chip Vile showed you is cheap, why not go for it?
I know you guys probably don't care, but my dad was yelling, having a fit because I mentioned buying a chip for my truck. He started saying how I'm not building a high performance racer (which I'm not) and I don't need some chip to give me the best performance out of my engine. He also said that if I buy this chip, then I'm screwed because nobody will work on it when there's a problem because it's a modification that is "too complex" or "not factory." That's the difference between him and I. When he does something, he'll do the bare minimum to get it to work. When I do something, I get everything I need to make my "project" the best it can be, even if it means spending some extra money.
So by not installing the chip, will the motor run like crap? How about harming the motor?
Tell your Dad, to properly take advantage of the money that was already spent, you need atleast a Factory Programmed Chip, otherwise it is going to be a dog and not run correctly.... Let him also know that nobody will want to work on somebody elses problem, when they haven't already taken the time to use the proper parts..... Also any Shop under the sun will be Happy to Repair anything within reason, despite the parts, cause that is how they make money..... Just to cover themselves, they will have you sign a Waiver saying that they are correcting your mistakes, and any damages or repairs needed will be paid for in full....
Besides if the Shop really wanted to be Pissy about different parts, they wouldn't touch it after you installed a 350 replacing the Factory 305, cause that was not Factory installed....
Honestly I would save yourself some trouble, and go to a good Wrecking/Salvage Yard, and find a Truck around your year with a 350 in it, & nab the Chip out of it.... Just make sure you touch a metal area of the truck, before you remove the Chip, and also disconnect your Battery Cables, and touch metal on your truck before swapping in the new chip.... Your touching a Metal Surface to ground out any static electricity
in your body or on your clothing, so you don't short the chip or ECM out....
Good Luck with your Pop's, I went through same battle, even same argument!!! Still get them from time to time, just easier to deal with since it's my Money,My Car/Truck, and I don't live with him.... ;D
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I guess he was just cranky. He's not always like that. He's just been busy. I'm going to go ahead and buy the chip. It's my money anyway, and he said I can buy whatever I want, he just doesn't think it's a good idea. Whatever. I'm going for it.
So right now my plan is to spend about 2 hours to get the 305 out. Either on that same day or another day I'll spend another 2 hours getting the 350 in. By "getting it in" I mean just that. No mods, no check ups, no connections. Then I'll spend another day connecting everything and getting it running properly.
These are the parts I plan to take from the 305 and use on the 350:
- Starter
- Pulleys
- Intake
- Headers
etc...
Does everything sound okay?
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Same flywheel teeth count? The starter is dependent upon it.
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Your dad should be thankful to have a son like you. Actually, the performance will increase and so will gas mileage , so it's certainly the better way to go. He'll understand things better when he gets his 1st ride...
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What year is the 305 vs 350? What year heads. If they are later model (87-up, the intake won't swap) I would also verify headers as some 305s had a bolt off.
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What year is the 305 vs 350? What year heads. If they are later model (87-up, the intake won't swap) I would also verify headers as some 305s had a bolt off.
The 305 is the original '87 motor. The motor I'm putting in is from an '88. Both heads on the motors are factory.
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Same motor, so there won't be any surprises.