Well I just am getting a 1979 Olds 88 with a 403 in it with 52,000 original miles from my girlfriends parents I am pulling out the 403 and what I think is a 350 trans, i will no more once i get it home, and I am going to scrap the rest for extra money for the build, and plus it is a pile of crap other than the motor. Here is the thing this is going to be a fun low budget motor build untill i can save up for the big block build and the beauty is it will drop right in place of my 307 because good ole small block olds use and same motor mounts and i can use the acessories from the 307 😀 . So here is where i need help i know that these motors make about 185 hp and about 300 lbft of tourqe, thats all fine and dandy but i am wondering some easy things to make some more power I was told that if you put a good cam and a set of olds 350 heads it will boost the power i also plan on gettin a set of dynomax headers for this application as well. Any suggestions on heads, cam durration, or any other port and pollish work or any other things is welcome.... once again this is a temporary budget build to satisfy me until the big block comes so this thing does not need to be a monster that will come later. Also any ideas about a rearend fix for now can i make my 7.5 strong enough or should i bite the bullet and by a 8.5 now.....
New Engine need input
- Thread starter HighHPCouch
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403 upgrades
Street 403 Build
Block: a "4A" - "4B" casting code, use main studs!
Pistons: Sealed Power Forged 10.2:1 Part # L2230F with a 0.040" head mill, will fit. KB Pistons #KB405-024 Forged 10.2:1 with a 0.040" head mill. also Aries, Diamond #P5403, Sealed Power, Venolia
Crankshaft: Get 1968-74 nodular iron crank #393654. Or 330 forged unit, casting #381919 or 388776.
Heads: Shave them .040" and Invest in Porting/Blend Bowl's in, send heads to J&S Machine
swap out to either "2" - "7" 350 heads, Add W-31 valves (2.000" intakes and 1.625" exhausts).
or keep them 4A (add W-30 valves w/2.072" intakes and 1.68" exhausts)
Full Roller Rocker Arm System with 8.400" x 5/16" pushrods
Camshaft: factory 409759 294/296* cam (Supercars Unlimited #14-240) and 300 lb springs (SU #14-060). or Mondello JM-20-22 SMT
Oil Filter: Wix #51258
Exhaust: 1-3/4" x 3" Headers
Hooker Super Comp #3108-1HKR, American Racing, M&P Proforfance
"X" Pipe:
Intake and Carb: Edelbrock Performer 3711. Modified heads go with the Edelbrock Performer RPM 7111 (2" taller than stock), also run a 1/2" Canton Racing Phenolic resin spacer between the carb and manifold. Keep your Q-jet, but get it modified.
Fuel Pump: Airtex AF40726 this pump is anodized in the same manor as factory pieces. and is rated at 80 GPH.
Carter M6108 this pump is stock appearing and is rated at 120 GPH.
Front Suspension: Front end rebuild kit #E-FRTKIT-G $206 (spohn), and TRZ kit. and '82-'92 F-body front sway bar (34 or 36mm)
Radiator: Aluminum #433918 at Autozone $95, and Aluminum Water Pump: $129
Rear Suspension: go with full TRZ setup.
For Rearend: install posi and 3.73 gears, and '82-'84 F-body aluminum rear brake drums.
or contact Quick Performance
Street 403 Build
Block: a "4A" - "4B" casting code, use main studs!
Pistons: Sealed Power Forged 10.2:1 Part # L2230F with a 0.040" head mill, will fit. KB Pistons #KB405-024 Forged 10.2:1 with a 0.040" head mill. also Aries, Diamond #P5403, Sealed Power, Venolia
Crankshaft: Get 1968-74 nodular iron crank #393654. Or 330 forged unit, casting #381919 or 388776.
Heads: Shave them .040" and Invest in Porting/Blend Bowl's in, send heads to J&S Machine
swap out to either "2" - "7" 350 heads, Add W-31 valves (2.000" intakes and 1.625" exhausts).
or keep them 4A (add W-30 valves w/2.072" intakes and 1.68" exhausts)
Full Roller Rocker Arm System with 8.400" x 5/16" pushrods
Camshaft: factory 409759 294/296* cam (Supercars Unlimited #14-240) and 300 lb springs (SU #14-060). or Mondello JM-20-22 SMT
Oil Filter: Wix #51258
Exhaust: 1-3/4" x 3" Headers
Hooker Super Comp #3108-1HKR, American Racing, M&P Proforfance
"X" Pipe:
Intake and Carb: Edelbrock Performer 3711. Modified heads go with the Edelbrock Performer RPM 7111 (2" taller than stock), also run a 1/2" Canton Racing Phenolic resin spacer between the carb and manifold. Keep your Q-jet, but get it modified.
Fuel Pump: Airtex AF40726 this pump is anodized in the same manor as factory pieces. and is rated at 80 GPH.
Carter M6108 this pump is stock appearing and is rated at 120 GPH.
Front Suspension: Front end rebuild kit #E-FRTKIT-G $206 (spohn), and TRZ kit. and '82-'92 F-body front sway bar (34 or 36mm)
Radiator: Aluminum #433918 at Autozone $95, and Aluminum Water Pump: $129
Rear Suspension: go with full TRZ setup.
For Rearend: install posi and 3.73 gears, and '82-'84 F-body aluminum rear brake drums.
or contact Quick Performance
I am a big fan of following what someone else has done if it worked; so if guys on this site give advice and have lots of Olds experience then you will be safe going down their respective roads.
I, on the other hand, pretty much completely plagiarized an article from a 1979 Car Craft entitled, "How to make your 403 Firebird fly" and it worked great. The prescription was very simple.
-1968-1970 code "C" big block heads; three angle valve job and port matching on the intake
-Edelbrock 350 Olds intake that was port matched to the 455 heads (now they sell the performer RPM large enough to just port match it for those heads)
-Hot cam, roughly equivalent to the Lunati bracket master 2 or performer RPM cam
-1-3/4" long tube headers
-Re-tuned carb
They were doing 12's immediately with this combo and it was in a loaded trans am with a TH350 and all the bells and whistles. They did have to pin the shaker scoop to the hood because the clearance was off when the intake sat up a little higher than stock. I don't know what that will do under a G-body hood, but someone here does.
I was impressed enough to try it and got similar results. I am an ULTRA LOW BUDGET guy though, so that is why I went that way.
I, on the other hand, pretty much completely plagiarized an article from a 1979 Car Craft entitled, "How to make your 403 Firebird fly" and it worked great. The prescription was very simple.
-1968-1970 code "C" big block heads; three angle valve job and port matching on the intake
-Edelbrock 350 Olds intake that was port matched to the 455 heads (now they sell the performer RPM large enough to just port match it for those heads)
-Hot cam, roughly equivalent to the Lunati bracket master 2 or performer RPM cam
-1-3/4" long tube headers
-Re-tuned carb
They were doing 12's immediately with this combo and it was in a loaded trans am with a TH350 and all the bells and whistles. They did have to pin the shaker scoop to the hood because the clearance was off when the intake sat up a little higher than stock. I don't know what that will do under a G-body hood, but someone here does.
I was impressed enough to try it and got similar results. I am an ULTRA LOW BUDGET guy though, so that is why I went that way.
High Roller- all of the things that you have mentioned seemed like they would in the long run be way out of budget i am considering all of that work for my 455 but not for this 403 this is a budget build it would be different if this was the motor that is staying in the car for a good long time but its not and this is just something to give my car a little more power and to keep my car on the road which my 307 is doing poorly now, but thanks for the input all help is appreciated i may ose some of it. Oh btw i forgot to mention i already have the full Hotchkis suspension under the car, that was last winters project then the motor took a crap.
KrisW- now that is more what i am talkin about quick and easy and CHEAP but i have a few questions for you the first one is can you get me a copy of that article, scan or maybe a web link, and second is do you have any place to read up on building Q-jets as far as parts and procedures, I want to do it myself, also which Q-jet to use the one on the 403 or the 307 one?
KrisW- now that is more what i am talkin about quick and easy and CHEAP but i have a few questions for you the first one is can you get me a copy of that article, scan or maybe a web link, and second is do you have any place to read up on building Q-jets as far as parts and procedures, I want to do it myself, also which Q-jet to use the one on the 403 or the 307 one?
The 307 quadrajet would most likely run lean on a 403 (unless it's from something else they are on almost every chevy pre 86) Also the one in the 403 has been calibrated for the correct flow rate to a 403. Also it most likely a bigger accelerator pump. IMO If you were going to mod one it would make sense to go with the one calibrated for the motor and then increase it's flow rate from there.
http://www.vetteprojects.com/kstyer/quadrajet.htm
Good tutorial on rebuilding a quadrajet.
Don't bother on a ccc. I took mine apart and it wasn't worth getting my hand dirty.
Good tutorial on rebuilding a quadrajet.
Don't bother on a ccc. I took mine apart and it wasn't worth getting my hand dirty.
Ok taking all of this into consideration....and the 455 falling through on me I am going to build this 403 now. Here is the deal i am still on a budget and the goal is to get my car back on the road by next spring but i want to do as much as possible by myself to save money by cutting labor time down. I have been doing lots of reading and i am confused on some things. The first being i have been seen people using BBO heads on these 403s?????? i guess i am so used to Chevy power idk what to say other than 
another thing is do i need a halo girdle for 400hp and under, in reality i would be happy with 350-400. And I would also like to spend aroud 1500 if possible on the motor. Now here are the things that i have found to be the restrictors on these motors:
Mains
Compression
Exhaust Flow
Is there a head swap that i can do to help the exhaust and compression without shellin out mounds of cash?
I am trying to keep the machine work to the basic level, port and polish the heads, block cleanup and rehone,etc..
Also is there a shop in MI that knows enough about these motors that i can feel safe taking this thing to, I am trying to save money and shipping parts to J&S in IL is not going to save me any money cause it is heavy crap.
BTW thanks for the info to this point!!!
another thing is do i need a halo girdle for 400hp and under, in reality i would be happy with 350-400. And I would also like to spend aroud 1500 if possible on the motor. Now here are the things that i have found to be the restrictors on these motors:Mains
Compression
Exhaust Flow
Is there a head swap that i can do to help the exhaust and compression without shellin out mounds of cash?
I am trying to keep the machine work to the basic level, port and polish the heads, block cleanup and rehone,etc..
Also is there a shop in MI that knows enough about these motors that i can feel safe taking this thing to, I am trying to save money and shipping parts to J&S in IL is not going to save me any money cause it is heavy crap.
BTW thanks for the info to this point!!!
People use big block heads because they flow much better for a 403. I am not positive if people also change to high compression pistons with those heads or not. You will be fine with out a girdle as long as you don't plan on revving the engine very high, like past 5,500 rpm's.
I don't know how close you are to Ohio, but there is M and J performance in Louisville, Ohio. They are very good with Olds engines and will do a good job with your heads. Depending on where you are, it may be worth the drive to have him do your work.
Check this out and look for 403 engines. http://www.realoldspower.com/phpBB2/vie ... e82158fda8 There should be some that are close to your needs and within your budget.
I don't know how close you are to Ohio, but there is M and J performance in Louisville, Ohio. They are very good with Olds engines and will do a good job with your heads. Depending on where you are, it may be worth the drive to have him do your work.
Check this out and look for 403 engines. http://www.realoldspower.com/phpBB2/vie ... e82158fda8 There should be some that are close to your needs and within your budget.
I have been watching the posting on you guys working on the Olds 403. I am working on one myself. It will be replacing the 350 in my 70 Olds. The 403 will have a the Eldelbrock heads. The 403 mandates having higher compression pisitons. The 4A heads have 80cc volumes and the big block heads are about the same..slightly less (about 77cc). The budget minded person would use a set of number 7a 72 heads which have 69cc. The CR on the 403 with about 77cc and .040 head gasket is about 9.8:1. If you stick with the 80+cc the CR is about 7.9:1. My previous car was a 79 T/A in stock form its CR was 7.9:1. The 72 heads can be ported to flow quite well. The 4A heads actaully had larger valves so if you milled thos down you had lots of potential and porting those would work. If you could find #5 heads those would be out of a W31 which were high flowing. (They are very rare). I am using a girdle on mine because the mains are webbed. With the girdle I'll need to limit it to no more than 6000RPM. I am still lamenting over cam choice. If you have any recommendations I'll take all the advice i can get.
HPcouch. I have a set of Olds 403 heads you can experiment on if you want to go the route of milling etc. I'll give them to you. You can't beat free. I have a set of 72 heads as well. Those I have to think about a bit.
HPcouch. I have a set of Olds 403 heads you can experiment on if you want to go the route of milling etc. I'll give them to you. You can't beat free. I have a set of 72 heads as well. Those I have to think about a bit.
Olds Engine Builders
Here's a list of Oldsmobile engine builders:
BTR Performance
Dave Smith Engineering
Dick Miller Racing
J&S Machine
Knowltons Thunderheads
M&J Proformance
Olds Performance Products
Rocket Racing Performance
Here's a list of Oldsmobile engine builders:
BTR Performance
Dave Smith Engineering
Dick Miller Racing
J&S Machine
Knowltons Thunderheads
M&J Proformance
Olds Performance Products
Rocket Racing Performance
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