305 to 350 CCC swap

[Jeff Eller]

I have a 1986 Monte Carlo LS that has 168,000 original miles on the drivetrain. This is a two owner car I bought a couple of years ago. I bought the car barely running because it had not been tuned up or taken care of and had a coolant leak at the back of the intake manifold at the crossover passage on the passenger of the intake manifold. Once I got the tune up, intake manifold issue corrected ands replaced all the necessities and got the car running the original 305 block cracked in cylinder number 8. The 305 was one of the HO motors, flat top pistons, 416 heads etc.
My question is: I'm wanting to continue to use the computer (CCC) and swap in a 350 cubic inch engine. I know I will have to rework the carburetor but do I need to do anything with the computer itself? I had a stage 1 aftermarket chip in the computer for the 305. Do I need to change the computer chip for a 350 engine say out of a carbureted 350 Camaro or Firebird or does this even matter? Does the computer even matter? I've seen people do this without changing the computer but just wondered if it works OK or not.
It would be great to hear from someone who has experience with this. Thank you

 

[Clone TIE Pilot]

The only thing is swapping in a 350 ESC module and knock sensor. But a lot of guys get away with using 305 esc modules and knock sensors on 350s.

 

[axisg]

^^ what he said ! Lots more info on MCSS as they tend to retain the CCC system more than others

 

[ed1948]

I'll be watching your progress.

 

[79 USA 1]

Jeff,
Had a 86 El Camino that had the LG4 305 in it at birth. After the purchase I came to realize it was on its 2nd 305 and had close to 250,000 on the body. I replaced the 305 with a 1976 vintage 355 small block, Flat top pistons, Iron heads, and a Crane Comp u Cam. I retained all the computer controls including stock computer controlled Q-Jet carb, added air tubes on long tube headers and true duel exhaust. Only change to the system I had made was to run a stock computer chip from a 86 Monte Carlo SS. The "performance" chips seemed to throw too much advance too fast at this engine and it would ping unless I ran 93 octane fuel or better. The stock SS prom chip worked perfect.

Hope this helps!
Bob S.

 

[airboatgreg]

How radical of a 350 are you installing??
factory stock?

My question is: I'm wanting to continue to use the computer (CCC) and swap in a 350 cubic inch engine. I know I will have to rework the carburetor but do I need to do anything with the computer itself? I had a stage 1 aftermarket chip in the computer for the 305. Do I need to change the computer chip for a 350 engine say out of a carbureted 350 Camaro or Firebird or does this even matter? Does the computer even matter? I've seen people do this without changing the computer but just wondered if it works OK or not.
It would be great to hear from someone who has experience with this. Thank you

My question is: I'm wanting to continue to use the computer (CCC) and swap in a 350 cubic inch engine. I know I will have to rework the carburetor but do I need to do anything with the computer itself? I had a stage 1 aftermarket chip in the computer for the 305. Do I need to change the computer chip for a 350 engine say out of a carbureted 350 Camaro or Firebird or does this even matter? Does the computer even matter? I've seen people do this without changing the computer but just wondered if it works OK or not.
It would be great to hear from someone who has experience with this. Thank you

 

[Jeff Eller]

How radical of a 350 are you installing??
factory stock?

My question is: I'm wanting to continue to use the computer (CCC) and swap in a 350 cubic inch engine. I know I will have to rework the carburetor but do I need to do anything with the computer itself? I had a stage 1 aftermarket chip in the computer for the 305. Do I need to change the computer chip for a 350 engine say out of a carbureted 350 Camaro or Firebird or does this even matter? Does the computer even matter? I've seen people do this without changing the computer but just wondered if it works OK or not.
It would be great to hear from someone who has experience with this. Thank you

The only thing is swapping in a 350 ESC module and knock sensor. But a lot of guys get away with using 305 esc modules and knock sensors on 350s.

Thank you very much for your help!!

 

[Jeff Eller]

Thanks to everyone for their replies and help. I should be good to go now. I will elaborate more on my combination I'm choosing for others soon and I will keep everyone posted and updated. Look me up on Facebook also.
Thanks again everyone.

 

[PBGBodyFan]

Depends on how mild or wild your 350 build is when retaining the CCC system and carb. The big thing is keeping a cam that is ECM friendly, IIRC. I have a 383 with the CCC system, runs great. ZZ4 chip when they were still available, but there are people who custom make/replicate these and it's a little cheaper too. A relatively mild 383, good street manners and 313 rwhp, good enough for me. I ran it with the original Q-Jet untouched for many years just fine, when it was time for a rebuild I had it done by Cliff's in Ohio, a good source for building Q-Jets and some minor tweaks were done at that time.

 

[Jeff Eller]

Depends on how mild or wild your 350 build is when retaining the CCC system and carb. The big thing is keeping a cam that is ECM friendly, IIRC. I have a 383 with the CCC system, runs great. ZZ4 chip when they were still available, but there are people who custom make/replicate these and it's a little cheaper too. A relatively mild 383, good street manners and 313 rwhp, good enough for me. I ran it with the original Q-Jet untouched for many years just fine, when it was time for a rebuild I had it done by Cliff's in Ohio, a good source for building Q-Jets and some minor tweaks were done at that time.

Hello and thank you for your response. I'm thinking about a 355 or 383 for my LS car. I was going to stay with a hydraulic roller camshaft listed in the extreme energy section on Comp Cams website, XR264HR - 12-412-8 camshaft I believe. It's made for a 305 or 350 CCC engine. I contacted Comp Cams and this is what they actually recommended. I hadn't really thought about it but I could just use one of the factory hydraulic roller cams I suppose like the ZZ4 cam. I used to be able to get these cheap, don't know about now. I'm just wanting a good driver with computer and air conditioning and 3.23 gear with the 200-4R transmission. I had spoken with Cliff Ruggles earlier this year about my combination thinking I was going to stay 305 at the time and he gave me some pointers on what to do to the computer quadrajet carb as I've always been a Holley carb guy since I drag raced for years. I'm sure I will contact Cliff again now with the larger engine. I'm basically going to go with an Eagle Specialties rotating assembly kit with flat top pistons, hydraulic roller and I'm deciding right now what heads I want to run. I'm thinking about just staying 355 since it's going to be a driver but who knows I may change my mind. I also have an Edelbrock 3701 and 3704 intake manifold depending on what type of heads I decide to use. I'm probably going to invest in a set of Hedman headers for the car since I missed out on a set of Hooker 2050 headers that are no longer produced. I have a modified stock transmission cross member for dual exhaust and I have an aftermarket transmission cross member for dual exhaust.
Wonder who could make or replicate the ZZ4 chip? I will find a knock sensor for a 1980's Camaro with a 350 as suggested above and some type of factory replacement or aftermarket chip as you have suggested after I gather a bit more information and learn more about the computer when swapping engines.
Any help would be greatly appreciated from yourself or anyone here on the forum.
Thank you again.