mods to 305 using stock prom
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Senior Member
Joined: Oct 2003
Posts: 528
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From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
mods to 305 using stock prom
Well I am selling a Complete 88 350 TPI Motor ,Wireing Harness ,and ECM. How Much do you guys think this is Worth? It ran fine 3 years ago but the car got in an accident and has not been started since. the owner lost the the keys.
PM me if you are interested.
And when I get the money (hopefully this summer) I am going to send my 85 305 TPI off and get it rebuilt. And I want to know what all mods can be done using the stock chip (I do not know how to burn proms and really don't want to learn on this car, mabye my next project car).
I am already planing on headers and high flow Cat with my current flowmaster. But what about Cam and heads. Also what about my injectors, I know my o-rings are worn but do I really need to replace the injectors or should I just replace the o-rings.
I am also planing some Eldebrock High-Flo runners w/stock base or SLP runners which ever one is better with stock base.
Any other mods would be appreciated but please keep it "stock prom friendly"
Could someone also tell me about how much HP I should expect.

PM me if you are interested.
And when I get the money (hopefully this summer) I am going to send my 85 305 TPI off and get it rebuilt. And I want to know what all mods can be done using the stock chip (I do not know how to burn proms and really don't want to learn on this car, mabye my next project car).
I am already planing on headers and high flow Cat with my current flowmaster. But what about Cam and heads. Also what about my injectors, I know my o-rings are worn but do I really need to replace the injectors or should I just replace the o-rings.
I am also planing some Eldebrock High-Flo runners w/stock base or SLP runners which ever one is better with stock base.
Any other mods would be appreciated but please keep it "stock prom friendly"
Could someone also tell me about how much HP I should expect.
Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
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From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
My original plans were to do that but after learning what all has to be done I am considering sticking with the 305.
Well their is one big reason and that is that I don't know how to convert my 85 Ecm/harness to the 88 Ecm/harness. I am trying to figure it out but then I would end up putting it all together and it would'nt work and I need this car for school. So I figured I would just sell the 350 and use the money for the 305 and then I would be almost garrenteed that would start the first time plus I get to keep the original block(which might be nice in 20 years when if I decide to sell it).
But then again I could just get a new chip burned. But I also know nothing about that.
What do you guys think of an 85 350 TPI corvette chip. I know they had aluminum heads but does that really effect it that much.
But what mods are possible with the corvette chip and where can I get one and how much.
Well their is one big reason and that is that I don't know how to convert my 85 Ecm/harness to the 88 Ecm/harness. I am trying to figure it out but then I would end up putting it all together and it would'nt work and I need this car for school. So I figured I would just sell the 350 and use the money for the 305 and then I would be almost garrenteed that would start the first time plus I get to keep the original block(which might be nice in 20 years when if I decide to sell it).
But then again I could just get a new chip burned. But I also know nothing about that.
What do you guys think of an 85 350 TPI corvette chip. I know they had aluminum heads but does that really effect it that much.
But what mods are possible with the corvette chip and where can I get one and how much.
Supreme Member
Joined: Aug 2001
Posts: 1,228
Likes: 1
From: Caldwell, NJ
Car: 88 IROC Convertible
Engine: 305 TPI
Transmission: Raptor 700
stick witht eh 305 if thats what makes you happy, don't let anybody tell you otherwise
def don't descreen the maf, one of hte worst things you could do, just run a search and you'll read tons of horror stories. unless you're making some major power the maf is not the bottleneck
my recommendations are def full exhaust, gut those airboxes, KN's, DEF port the tpi but not too much otherwise you'll lose a lot of your low end
cam and heads are also obviously a great mod but not all to "stock prom" friendly depending on how big of a cam you choose and such. You'll never gain the full potential of those mods without some tuning.
as for your injectors no need to replace them unless you really feel like it, personally i would just get all the injectors cleaned at a local shop that has the machine to do so. Then get all the gaskets and orings and pop em back in.
aso another good mod is the adjustable fuel pressure regulator. Most people on teh boards like the Holley unit but do a search for more info on that.
do not put that 85 chip into your car, the aluminum heads do make a bit of a difference, no point in wasting money on it. Your stock chip will do just fine for the smaller mods you plan on doing. basically what i'm saying is if you want to tap the full potential of all the mods you're gonig to have to do some prom tuning at one point or another, just depends on what mods you plan on doing
theres a bunch of other free mods and such that you could do with your motor, take a look at the tech articles, tehres a bunch of good info in there and do a search for this, i'm sure you'll get a number of responses
def don't descreen the maf, one of hte worst things you could do, just run a search and you'll read tons of horror stories. unless you're making some major power the maf is not the bottleneck
my recommendations are def full exhaust, gut those airboxes, KN's, DEF port the tpi but not too much otherwise you'll lose a lot of your low end
cam and heads are also obviously a great mod but not all to "stock prom" friendly depending on how big of a cam you choose and such. You'll never gain the full potential of those mods without some tuning.
as for your injectors no need to replace them unless you really feel like it, personally i would just get all the injectors cleaned at a local shop that has the machine to do so. Then get all the gaskets and orings and pop em back in.
aso another good mod is the adjustable fuel pressure regulator. Most people on teh boards like the Holley unit but do a search for more info on that.
do not put that 85 chip into your car, the aluminum heads do make a bit of a difference, no point in wasting money on it. Your stock chip will do just fine for the smaller mods you plan on doing. basically what i'm saying is if you want to tap the full potential of all the mods you're gonig to have to do some prom tuning at one point or another, just depends on what mods you plan on doing
theres a bunch of other free mods and such that you could do with your motor, take a look at the tech articles, tehres a bunch of good info in there and do a search for this, i'm sure you'll get a number of responses
Supreme Member
Joined: Mar 2002
Posts: 1,654
Likes: 2
From: Lower Salford, PA
Car: 1987 Camaro Z-28
Engine: 6.3L Victor EFI
Transmission: Tremec TKO 600
Axle/Gears: Moser 9"/4.11 Trac-Lok
Here's an idea, sell the 88 TPI intake, ECM & wiring, send the 350 long block out or rebuild it yourself, all while still driving your 305. Then swap the 305 for the 350, using the 85 TPI setup.
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Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
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From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
Originally posted by Ricktpi
Here's an idea, sell the 88 TPI intake, ECM & wiring, send the 350 long block out or rebuild it yourself, all while still driving your 305. Then swap the 305 for the 350, using the 85 TPI setup.
Here's an idea, sell the 88 TPI intake, ECM & wiring, send the 350 long block out or rebuild it yourself, all while still driving your 305. Then swap the 305 for the 350, using the 85 TPI setup.
But what I was thinking of was get the 85 350 vette chip to go with the 88 350 and then mabye just buy alum. heads. What are your thoughts on this.
Mabye I won't be selling the 350
Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
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From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
nikh23: Keeping the 305 does not make me happy, but I will if I have to. And then when know alot more about tuning go with the 350.
Where do you guys recomend geting good chips or where I can learn the basics of tuning(right now I know very little)
Where do you guys recomend geting good chips or where I can learn the basics of tuning(right now I know very little)
Supreme Member
Joined: Mar 2002
Posts: 1,654
Likes: 2
From: Lower Salford, PA
Car: 1987 Camaro Z-28
Engine: 6.3L Victor EFI
Transmission: Tremec TKO 600
Axle/Gears: Moser 9"/4.11 Trac-Lok
If you swap the injectors, you will have to something with the chip, either swap it or reburn it for the bigger injectors. For a temporary fix you could put adjustable fuel pressure regulator on & up the FP to supply more fuel.
Supreme Member
Joined: Mar 2002
Posts: 1,654
Likes: 2
From: Lower Salford, PA
Car: 1987 Camaro Z-28
Engine: 6.3L Victor EFI
Transmission: Tremec TKO 600
Axle/Gears: Moser 9"/4.11 Trac-Lok
There is a ton of info on this board on PROM burning. The PROM DIY forum is a good place to start. Check out Traxions article on PROM burning.
Senior Member
Joined: Jul 2002
Posts: 519
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From: marlborough/dartmouth, MA
Car: 1988 IROC-Z
Engine: LB9
Transmission: 700R4
Originally posted by nikh23
def don't descreen the maf, one of hte worst things you could do, just run a search and you'll read tons of horror stories.
def don't descreen the maf, one of hte worst things you could do, just run a search and you'll read tons of horror stories.
Senior Member
Joined: Aug 2001
Posts: 610
Likes: 0
From: fredericksburg, va
Car: 85 ta ws6 KITT
Engine: Lb9
Transmission: th350
i've descreen the MAF on both my 85 305 and 86 lt1 with 0 problems.....
don't put on alum. vette heads? no difference? The 8113 heads are one of the most recommended heads, price wise for the 305. there's also the s/r torquer heads, but the 8113's can usually be found cheaper. That's what i'm using and will be doing a home port job. you could also just port your stock heads, for decent gain, depending on which casting you have.
do a search for 305 aluminum heads or something. you'll find plenty of good info.
don't put on alum. vette heads? no difference? The 8113 heads are one of the most recommended heads, price wise for the 305. there's also the s/r torquer heads, but the 8113's can usually be found cheaper. That's what i'm using and will be doing a home port job. you could also just port your stock heads, for decent gain, depending on which casting you have.
do a search for 305 aluminum heads or something. you'll find plenty of good info.
Senior Member

Joined: Oct 2002
Posts: 694
Likes: 0
From: Glasgow Kentucky
Car: 04 Vette
Engine: LS1
Transmission: 4L60E
Axle/Gears: 2.73
Here is how to convert your harness to work with the 88 ecm.
http://www.eecis.udel.edu/~davis/z28/ecm_swap/
http://www.eecis.udel.edu/~davis/z28/ecm_swap/
Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
Likes: 0
From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
OK, so right now I have preety much decided that I will just keep my harness and 870 ECM and put in the 350 TPI and then either burn my own chip or buy one. But if I buy one where is a good place to get one less then $300 I think fastchips.com will make me one but they want $300 and I can almost do it myself for that much.
Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
Likes: 0
From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
Just got this E-mail from www.perfomanceresource.com and was wondering if these prices sound good. And also He/She mentioned that the 85 vette chip might work If so what are my chances finding one used in a juckyard or any where else for that matter?
The only real mods I will be doing is high flow runners, headers and high flow cat.
The only real mods I will be doing is high flow runners, headers and high flow cat.
Thread Starter
Senior Member
Joined: Oct 2003
Posts: 528
Likes: 0
From: NorthEast GA
Car: 85 Trans Am
Engine: 305 TPI
Transmission: 700-R4
Mabye it would help if I posted the e-mail
If you are using the '85 ECM a high performance chip costs $149.95 and if you have extensive internal engine modifications and need a custom chip, the cost will be $385. You may also be able to use an '85 Corvette prom, also $149.95. Thanks
If you are using the '85 ECM a high performance chip costs $149.95 and if you have extensive internal engine modifications and need a custom chip, the cost will be $385. You may also be able to use an '85 Corvette prom, also $149.95. Thanks
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