Good thing it's an auto with a stock engine.
CK5
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I'm bringing this thread back from the dead! It's HOT out now and I need to address some issues with the shop truck to make it better for summer. Brother's had a good sale on a nice radiator/electric fan combo so I'll be putting that in along with a new water pump and intake manifold. I also finally got the correct power window kit from Brother's, so those will be going in too. When that's all done I'll also need to troubleshoot the A/C and see why it's not blowing cold anymore.
First is the intake manifold. I had put an Edlbrock Performer intake manifold on only to discover that a TBI doesn't like a dual plane manifold... Apparently at lower RPM the fact that 2 injectors are spraying in one side and 2 in the other makes it idle rough (I have noticed this). Last year I did a bandaid by throwing on a 2" spacer, but it still didn't idle right and bogged pretty bad at low RPMs. I picked up a Torker II intake to swap that out (since I was draining the coolant anyways).
Side by side comparison between the intakes:
We managed to get the intake installed (sorry no pics) but ran into an issue with the radiator. Apparently on this body style truck there was an Heavy Duty and a Regular Duty radiator that used different hold downs. At some point the PO swapped the HD ones that would have been stock in the C20 with the RD ones, so I've got the HD ones on order, hopefully they'll be in this week because this radiator should be a drop in replacement.
Radiator comparison:
Hopefully I'll get the rest of the parts in this week and can get moving on the truck again. It will be nice to be able to use it again (way too hot to drive it without A/C).
First is the intake manifold. I had put an Edlbrock Performer intake manifold on only to discover that a TBI doesn't like a dual plane manifold... Apparently at lower RPM the fact that 2 injectors are spraying in one side and 2 in the other makes it idle rough (I have noticed this). Last year I did a bandaid by throwing on a 2" spacer, but it still didn't idle right and bogged pretty bad at low RPMs. I picked up a Torker II intake to swap that out (since I was draining the coolant anyways).
Side by side comparison between the intakes:
We managed to get the intake installed (sorry no pics) but ran into an issue with the radiator. Apparently on this body style truck there was an Heavy Duty and a Regular Duty radiator that used different hold downs. At some point the PO swapped the HD ones that would have been stock in the C20 with the RD ones, so I've got the HD ones on order, hopefully they'll be in this week because this radiator should be a drop in replacement.
Radiator comparison:
Hopefully I'll get the rest of the parts in this week and can get moving on the truck again. It will be nice to be able to use it again (way too hot to drive it without A/C).
Single plane should be listed as a requirement for any TBI. It made a world of difference on my FAST system.
I know right? I just happened to see an episode of Engine Masters that talked about it. The spacer made it better for sure, but I think the single plane will make it much better.
Wow! I feel like you guys have given me serious enlightenment. I had never heard of using single plane with a TBI system. I've always thought the idle on the 454 in the crew cab wasn't as smooth as it should be. I was even thinking just the other day that the carb'd 73 idled smoother than the EFI'd crew cab. One of those things I wish I had read before doing my motor swap. 
@r3dd0g I'll be curious to see if the real world driving results yield the expected results.
I don't know if it's the same for your vintage truck, but on the 73 I figured out there were 2 different HD radiators for AC equipped pickups. One is taller and the other is thicker. Mine has the "typical" shorter radiator with a thicker core. Of course this is the most expensive replacement version.
@r3dd0g I'll be curious to see if the real world driving results yield the expected results.
I don't know if it's the same for your vintage truck, but on the 73 I figured out there were 2 different HD radiators for AC equipped pickups. One is taller and the other is thicker. Mine has the "typical" shorter radiator with a thicker core. Of course this is the most expensive replacement version.
From what I saw there were only two different ones for the 67-72 vintage. HD and RD (4 core and 2 core I think).
beags86
Eastbound and Down
FYI Scott, they're only talking about aftermarket EFI systems like fast, the sniper, and fitech, excetera.Wow! I feel like you guys have given me serious enlightenment. I had never heard of using single plane with a TBI system. I've always thought the idle on the 454 in the crew cab wasn't as smooth as it should be. I was even thinking just the other day that the carb'd 73 idled smoother than the EFI'd crew cab. One of those things I wish I had read before doing my motor swap.
@r3dd0g I'll be curious to see if the real world driving results yield the expected results.
I don't know if it's the same for your vintage truck, but on the 73 I figured out there were 2 different HD radiators for AC equipped pickups. One is taller and the other is thicker. Mine has the "typical" shorter radiator with a thicker core. Of course this is the most expensive replacement version.
You're running a sniper it would totally be worth it to swap to a single plane.
Yeah, I was thinking the Sniper on my crew cab.
I have FiTech running on 3 vehicles (including my truck) with a dual plane manifold. No issues.
I still guarantee you that all 3 would run better with single plane manifolds.
I was going to say "no issues your are aware of."
beags86
Eastbound and Down
Matt has motor trend on demand. He's seen the episode I'm sure.
Like I said, they all run great and no different than the FiTech installs I’ve done with a single plane intake manifold.
While FiTech says it doesn't matter, it seems actual user experience is different.
https://www.chevelles.com/forums/89-efi/1004665-dual-single-plane-intake-efi-myth-busting.html
I'm not sure why FiTech says it doesn't matter, if you think about it the EFI system is spraying fuel for each cylinder individually. At low RPM half the fuel for each cylinder is being sprayed into the wrong intake plenum and isn't going to stay atomised. It won't be noticeable up top, but down low it will.
I'll let you know how it works out in my truck, but I know since I use it as a truck it gets bogged down low frequently and it currently runs very poorly at low RPM high load (blows black smoke, stalls etc.).
https://www.chevelles.com/forums/89-efi/1004665-dual-single-plane-intake-efi-myth-busting.html
I'm not sure why FiTech says it doesn't matter, if you think about it the EFI system is spraying fuel for each cylinder individually. At low RPM half the fuel for each cylinder is being sprayed into the wrong intake plenum and isn't going to stay atomised. It won't be noticeable up top, but down low it will.
I'll let you know how it works out in my truck, but I know since I use it as a truck it gets bogged down low frequently and it currently runs very poorly at low RPM high load (blows black smoke, stalls etc.).
It makes perfect sense when you think about how carbs rely on the vacuum to pull fuel down and into the needed area where the injector injects it when needed not where it’s needed.
Actually FiTech says it can matter, I spoke to a rep about it years ago when I did my first install on a 500hp built 383 with a dual plane manifold. That’s one of the vehicles that hasn’t had an issue with it.
Hopefully the manifold swap fixes your problems.
Carb or EFI? We're strictly talking about aftermarket throttle body EFI.
Maybe FiTech is different, maybe they only spray one injector at low RPMs to the correct side of a dual plane intake. I don't know the answer to that. I do know that there is tons of information out there saying that this is why my engine doesn't run well at low RPM. Out of curiosity what is your idle set at? I'm idling at 700 with a stock Goodwrench 350.
I have a 454 but it’s set to 700 (warm setting). The two other 350’s are set to 700 and 750 IIRC.
