Author Topic: Engine swap in progress...need tips/answers on L6 to SBC conversion  (Read 7875 times)

Offline thefarmboy21

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So all weekend I've been dog to the rain the get started on the swap. Finally today it cleared up after church long enough to pull the 350 from the truck it was in (ironically enough a 78 Ford Hi Boy DERBY truck) and got it in the garage for a few fresh gaskets amongst all the other stuff needed. Hope to start pulling the tired old 292 in the morning.

Before I start though, I have a few questions:
1. Pros/cons on 12" clutch vs 11" or 10"???
2. Need a cheap exhaust system(header back)..any recommendations? I really can't afford a $4-$500 exhaust. And I prefer 2.5" because the motor is fairly stout.
3. Will the 6cyl throttle linkage and such all work fine so long as I have the piece that bolts to the intake?
4. What are the torque specs on the flywheel to crank and pressure plate to flywheel? And do I use lube/loctite?
5. Anyone know the part # or who even carries the timing cover/balancer repair sleeve and seal? I got my last one at Autozone but I couldn't even get a part number to come up yesterday.
6. what heater core line goes where on the 350?

I'm sure I'll need more advice as I progress. I've done lots of SBC swaps, but nothing into a street legal vehicle, let alone without all fabricated parts. THANKS!!!
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #1 on: July 20, 2014, 10:40:39 PM »
OHHH, I just remembered my biggest question.....what's the best way to mount my power steering pump to a motor with No acc hole Double Humps?????
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline Stewart G Griffin

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #2 on: July 21, 2014, 06:07:54 PM »
1) i Have no idea

2) Can you weld?  If not, this is one area where you may have to spend $4-500 because exhaust fumes ARE DANGEROUS.

3) Not sure right now.  Although my parts catalogue lists the exact same part number for L-6 and small block for the 73 models.  You might try yours first.

4) Not sure, what yr is your truck?

5) Are you talking about the seal of the hole where the balancer goes into?

6) If you can show a picture of your intake this can help.
« Last Edit: July 26, 2014, 10:35:36 AM by bd »

Offline Stewart G Griffin

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #3 on: July 21, 2014, 06:11:48 PM »
As far as the p/s pump, i'm not sure if it's the best way but Speedway sells mounts that attach to the water pump or block:
http://www.speedwaymotors.com/Search?query=power+steering+mounts

Offline FlatBlack77

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #4 on: July 21, 2014, 10:33:42 PM »
heres some ideas for exhaust systems. scroll down to the truck section
http://www.jegs.com/p/Dynomax/Dynomax-Header-and-Manifold-Dual-Kits/744726/10002/-1

the price doesnt include mufflers but you should be able to use some cheap jegs brand glasspacks or something
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #5 on: July 22, 2014, 05:38:39 AM »
Well thanks for all the help this far, but the project is currently at a stand still. As I was taking the headers off the 350, I was "reading" the spark plugs and looking at the exhaust valves because I was affraid I might have a little blow-by, because the oil always smells a little like gas. WELL......7 of the exhaust valves were creamy/white but 1 was oily and black. HOWEVER, ring blow-by was not the cause.....the bronze valve guide had totally shoved through the cylinder head. Upon further inspection I found several others that have moved as well. I haven't pulled the intake yet, but I have a feeling the intake valves will be in the same mess. So I'm going to check compression and maybe throw a set of 1.94's on it for the time being or possibly borrow the motor from my 77 for now. Either way the plans of my torque monster grandpa truck will have to wait. Hopefully the old double humps can be fixed because I really hate to lose such a good set of heads. They're HEAVILY worked heads from a modified dirt car....2.055/1.60 undercut valves, bronze guides, zero extra metal anywhere. They make crazy power with my COMP 4x4 cam. Oh well.....such is the life of a gear head.
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #6 on: July 22, 2014, 06:34:22 AM »
My intake CURRENTLY on my 350 is an Edelbrock Performer RPM Air Gap. The truck is an 86, but regardless the bottom end will be a 2-piece main (pre 1985 block) And for simplicity of my warranty files, I bought the new 12" clutch for a 77 K10.

However depending on if and what heads I swap to my bottom end I may end up with a set of low power swirl ports from a TBI truck and a plain Edelbrock Perfromer intake that I have collecting dust that matches the odd ball TBI heads. Ideally I would either fix my double humps or throw my vortecs on it, BUT both cases would ensue more costs and this really is a temp motor anyway.....I hope. The plan is to build my 97 Vortec motor for it, making lots of TQ and not killing me in fuel.
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #7 on: July 22, 2014, 12:52:21 PM »
Also: yes I can weld. The seal I'm talking about is the timing cover/balancer seal and a speedy sleeve that you press over the balancer nub where the crank fits in. It's basically a quick fix to cover the groove cut in the balancer by years of spinning in the timing seal.
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline roger97338

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #8 on: July 25, 2014, 02:54:05 PM »
For your exhaust, a pair of cherry bomb header mufflers might work on your truck. They didn't work on mine when I swapped the L6 for a SBC. If I remember right, one side would fit, but the other wouldn't because of the way the transmission cross-member was shaped. I used a TH-400, so the x-member might not be in the way for other transmissions.

For the power steering pump bracket, if you're just trying to make something to get you by for now, you should be able to hack up your existing power steering pump bracket and your alternator bracket with a hacksaw/grinder/torch/broken chisel & hammer combo and make something that will work. Work might be overstating it, lets say 'work-ish.'

And I don't remember what I used for a throttle cable at first, but soon after I installed a Lokar cable and bracket.

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #9 on: July 25, 2014, 09:57:28 PM »
Well plan B (since the double humps are messed up) is to throw on my swirl port heads, a performer intake and just drop it in the truck. Then either some header mufflers or a cheap exhaust kit. I was just hoping I could find a 2 1/2" kit rather than 2 1/4" pipes. I was also hoping there was a kit that came with mufflers but oh well, I'll piece something together. I'll give some updates tomorrow evening or Sunday I'm hoping.
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline FlatBlack77

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #10 on: July 26, 2014, 05:23:26 AM »
i got one of those cheap universal dual exhaust kits from jegs and 2 glasspacks to make my own exhaust for from long tube headers back . such a pain in the rear. but i wanted 2 1/2 inch not 2 1/4 like you said. everything would have been easy but as said above the crossmember is in the way.

it ended up working and sounding good but it looks like poop and i had to go under the crossmember so it hangs down farther than id like.

next time im getting the dynomax kit. heck i might get the kit just to replace my hack job.
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #11 on: July 26, 2014, 10:07:34 AM »
Do any of the kits come with mufflers or am I going to have to get those too? Anyone have the cheap 2 1/4" kit with the Jegs mufflers?
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963

Offline FlatBlack77

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #12 on: July 26, 2014, 10:46:09 AM »
im pretty sure none of the kits actually come with mufflers.

you can get Flowtech glasspacks for $19 each. and jegs is free shippingn and handling
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Online bd

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #13 on: July 26, 2014, 11:47:36 AM »
...The seal I'm talking about is the timing cover/balancer seal and a speedy sleeve that you press over the balancer nub where the crank fits in. It's basically a quick fix to cover the groove cut in the balancer by years of spinning in the timing seal.

For GEN-I two-piece rear main small blocks, use:
Felpro 16202 (plus 16312 install tool); National Bearings & Seals 99176; Pioneer HB-4121; SKF 99176; Victor 66597RS & A228...

AutoZone

JEGS

Napa Auto Parts

O'Reilly Auto Parts

Summit Racing
Rich
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Offline thefarmboy21

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Re: Engine swap in progress...need tips/answers on L6 to SBC conversion
« Reply #14 on: August 04, 2014, 11:49:43 AM »
I FINALLY got around to pulling the 6-cylinder out, now I have a question....
ARE THE MOTOR MOUTS DIFFERENT?!?! I thought it was a direct drop in for a 350 but looks like the mount on the passenger side needs moved back? Also are the mounts mounted to that cross brace or can I just move the one back? This really put a kink in my plans.
AMSOIL DEALER # 5583011
86 Chevy K20 Custom Deluxe-Grandpa bought it new 11/20/85
77 Chevy K10 Custom Deluxe-Dad's first truck
69 Chevy C30 flatbed-Grandpa's farm truck
1950 International L-112-Grandpa bought it new, parked in 1963