TBIThrottle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.
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need some advise on putting a 72 355 motor in my 89 camaro TBI question
im trying for the life of me to figure out how i would go about doing this. the 355 has old heads but the motor has been gone through and id rather not change the heads so the factory tbi intake works cause they have the different bolt angle in the middle bolts.so i was thinking about getting a egr edelbrock manifold and a plate adapter from a 454 tbi so i can bolt it to the intake. is there an easier way to do this? also the heads are stock but i have a .488 lift comp cam and its bored .30 over. will i have an issue with the fuel pump or a stock 350 tbi unit? just getting some answers to some of the questions ive come up with. thanks
__________________ 89 Camaro Convertible (Work in progress)
Black with Ram Air hood
350 bored .30 over with 327 stock heads right now
T5 transmission in car right now
getting into the chip programming now.
working on frame right now and floor pan...
will be running tbi on car
next on the list is new top and making fully functional ram air.
Re: need some advise on putting a 72 355 motor in my 89 camaro TBI question
I would also like to add to that: I have found that if you purchase some 3/4" solid tube stock you can "slice" the angle into the bar stock then drill a hole in the center. When your done you will end up with a washer that is thicker on one side than the other. In my opinion it distributes the pressure more evenly.
You will also want to modify your dipstick. I took my stock dipstick and trimmed the portion of the tube where the stick slides in until it read "full" on the stick. If you use your factory dipstick on the old motor it wont read correctly unless you do this.
You will aslo have to block off plate your mechanical fuel pump on the early block.
If your using roller rockers and tall valve covers, be aware that you will not be able to remove the valve cover easily if your using AC. The manifold on the back of the ac unit projects too far to allow you to remove it easily. Recharge your AC AFTER your valve adjustments are done.
Be sure you use the water pump from the late model block...not the early block.
If your using a gear drive, disable any knock retard in your chip. The ecm hears the whine as a knock.
You will also have to switch out your flywheel.
Other than that it's pretty simple. Other than the intake trick, everything bolts up just like it was on the original motor.
Hope this helps, Brandon
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I further read your post...You will also need to farmilurize yourself with tuning. Your are changing the airflow considerably and will need tuning...especially at idle.
Last edited by Brandon2350; 04-26-2008 at 11:21 PM.
Reason: Automerged Doublepost
Re: need some advise on putting a 72 355 motor in my 89 camaro TBI question
Your fuel delivery system is also adequate...with the exception that your stock injectors may not be large enough without actually knowing what your running.
If money is an issue, Tune it with the tbi you already have then when you get everything running pretty decent swap in a 2" tbi to allow it to breathe. Getting enough air is a concern with your combo but it will run decent using what you have.
Re: need some advise on putting a 72 355 motor in my 89 camaro TBI question
Since i have to get an intake that has an egr valve on it cause id rather not use a stock intake i was thinking about this
SB-Chevy Intake Manifold
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Idle-6000 RPM
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High rise/dual plane
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Height: 3.68" front/5.02" rear
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Port size: 1.9" tall/1.16" wide
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Square flange carb mounting
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EGR provision 510-300-48 found this on ebay
and to get the throttle body on that i found this
THIS WILL BOLT TO ANY QJET OR INTAKE THAT HAS A SPREADBORE BOLT PATTERN WHICH IS 4 & 1/4" TO 5 & 1/2" CENTER OF BOLT HOLES. THROTTLE BORE HOLES ARE 2". YOU CAN PUT THIS ON A SPREADBORE INTAKE, THIS WAY YOU DON'T HAVE TO BUY GASKETS & A T.B. INTAKE. YOU CAN RUN A 4.3 350 OR 454 T.B. ON THIS ADAPTER. GM P/N 10085769. IT IS 1 & 3/4" TALL, USED & ALUMINUM. THIS ALSO HELPS GET THE GAS UP OFF THE INTAKE TO COOL IT OFF FOR BETTER PERFORMANCE
do you guys think this will work or am i in the wrong boat?
Last edited by GMZombie; 05-04-2008 at 01:20 PM.
Reason: forgot
Re: need some advise on putting a 72 355 motor in my 89 camaro TBI question
Nope...Your on the right track, but hood clearance might be a problem though. To give you an idea...I have an Edelbrock Performer intake. I purchased a 2" TBI unit from a 454 then I used the exact same adaptor in your pic to bolt it up to the intake. Then I took my stock air lid and placed it on top of the tbi. The complete unit ( bottom of manifold to top of air cleaner lid measured 13" +) This is considerably taller than the factory combo. I'm bolting this unit up in a 93 pickup and it looks like it will just clear by about 1/2".
It will work but I'm thinking clearance might be a problem in a car application unless you find a lower profile air cleaner assembly.