My 1973 K10 Chevy Cheyenne

[srimes]

Thanks for the info. I will await Blueprint's response. It does seem odd because that 383 stroker I sent in the original post (the wrong link) is externally balanced front and rear. The 396 stroker for whatever reason lists as internally balanced front and externally balanced rear.

My research suggests I'll need the McLeod 460265 flywheel and the McLeod 560222 counterweight kit.

I don't know enough about engine building, but how do you get the flywheel correctly weighted to the 3.875" crank? I assume you can't just slap on counterweights without knowing how many you need on there, right?

Blueprint will have the answer for your motor of course.

The 400 sbc was externally balanced with standard weights on the harmonic balancer and flex plate or flywheel. I would expect the builder to balance the engine with the standard balancer and flywheel, as there's no way to figure out just how much weight to add once the engine is assembled.

So when it says "internal front, external rear" it's calling for a a neutrally balanced harmonic balancer (like used on a 350) and externally balanced standard flywheel like what's used on a 400.

At least that's what I expect them to say.

 

[Chris]

Blueprint will have the answer for your motor of course.

The 400 sbc was externally balanced with standard weights on the harmonic balancer and flex plate or flywheel. I would expect the builder to balance the engine with the standard balancer and flywheel, as there's no way to figure out just how much weight to add once the engine is assembled.

So when it says "internal front, external rear" it's calling for a a neutrally balanced harmonic balancer (like used on a 350) and externally balanced standard flywheel like what's used on a 400.

At least that's what I expect them to say.

That's what ChatGPT is telling me. It's saying that I need the McLeod neutral balanced flywheel and then the McLeod counter weights to go with it. Of course I don't know how many of those counterweights to add, but I suspect Blueprint will be able to tell me.

Just trying to make sure I've got everything squared away before I start this swap. I've converted many cars from auto to manual in the past, but never something like this. I was mostly doing it on older VWs and BMWs in the past.

 

[srimes]

That's what ChatGPT is telling me. It's saying that I need the McLeod neutral balanced flywheel and then the McLeod counter weights to go with it. Of course I don't know how many of those counterweights to add, but I suspect Blueprint will be able to tell me.

Just trying to make sure I've got everything squared away before I start this swap. I've converted many cars from auto to manual in the past, but never something like this. I was mostly doing it on older VWs and BMWs in the past.

Blueprint will say something like "you need a flywheel balanced for a 1980 SBC 400."

The McLeod is a multi-application part, so it's a case of looking over their instructions to match the engine it's going on. Most likely:

’70 – ’85 383/400 Install small weight (weight with sharp corners, 4” wide) in position C. Attach with suppliedscrews.’

https://www.mcleodracing.com/produc...lation_instruction-instruction_file-93-v1.pdf

 

[Chris]

Blueprint will say something like "you need a flywheel balanced for a 1980 SBC 400."

The McLeod is a multi-application part, so it's a case of looking over their instructions to match the engine it's going on. Most likely:

’70 – ’85 383/400 Install small weight (weight with sharp corners, 4” wide) in position C. Attach with suppliedscrews.’

View attachment 652110

https://www.mcleodracing.com/produc...lation_instruction-instruction_file-93-v1.pdf

Good deal! That seems easy enough to follow.

I'm glad you guys caught this before anything shipped out. I was looking over the invoice and it clearly states on the McLeod flywheel, "for internally balanced engine". Wouldn't have been the end of the world, but it would just be another return hassle.

 

[ColoJeep]

Am I setting myself up for a big problem here do you think? I’m asking that because again, I don’t know how you would correctly balance a flywheel with counterweights unless the engine was spinning and you had some sort of balancer machine.

Chris , you should just have to install a correctly weighted flywheel , which you can easily do. The true challenge is finding someone at Blueprint that knows how much weight at what hand position on the flywheel. In theory it should be at the same position that it is on your current flexplate. The second issue is finding someone to install Mallory metal in the correct position and weight . Hopefully someone at Blueprint is on the ball and willing to assist you. The truck will be cool if you can get through the issues . You got this man !

 

[Chris]

Chris , you should just have to install a correctly weighted flywheel , which you can easily do. The true challenge is finding someone at Blueprint that knows how much weight at what hand position on the flywheel. In theory it should be at the same position that it is on your current flexplate. The second issue is finding someone to install Mallory metal in the correct position and weight . Hopefully someone at Blueprint is on the ball and willing to assist you. The truck will be cool if you can get through the issues . You got this man !

Good to know!

What a can of worms I've opened. Now I've decided since the dash is apart I may as well just paint the entire dash white to match the exterior. So it looks like I'll be masking that off and looking for a paint gun.

As you know the vehicle came with one EFI tank (from Tanks Inc.). The previous owner bought one EFI tank and pump from them and left the other tank in factory configuration. He then ran a fuel transfer pump from the other tank to the new EFI tank. In theory you could hit a switch on the dash and it would transfer fuel from the old carb tank to the new EFI tank. Unfortunately none of it worked and I like to do things the right way.

I figured I'd keep that EFI tank and pump and just buy one more to replace the one on the other side. Well, curiosity got the best of me so I opened up the EFI tank that came with it today and removed the fuel pump. Nothing but rust inside of it! The fuel pump had rust flaking off of it. The inside of the tank was rusty as hell! Flakes everywhere! Thank goodness for fuel filters

Anyways, I had to order another EFI tank, pump, and fuel level sender from Tanks, Inc. today. No way I'm putting that tank back on there.

Makes me wonder how all that rust got in there. Maybe it was the ethanol in the gas, or maybe he frequently stored it with little to no fuel in the tank. Either way, I'm glad I looked into that because I almost just left it alone since I figured it was okay.

At the rate this is going next thing you know I'm going to be swapping in an LS7

 

[ColoJeep]

That's what ChatGPT is telling me. It's saying that I need the McLeod neutral balanced flywheel and then the McLeod counter weights to go with it. Of course I don't know how many of those counterweights to add, but I suspect Blueprint will be able to tell me.

Just trying to make sure I've got everything squared away before I start this swap. I've converted many cars from auto to manual in the past, but never something like this. I was mostly doing it on older VWs and BMWs in the past.

Hopefully , someone will know the weight difference to properly balance a 3.875" forged crank vs. a 3,750" cast crank .

 

[ColoJeep]

Good to know!

What a can of worms I've opened. Now I've decided since the dash is apart I may as well just paint the entire dash white to match the exterior. So it looks like I'll be masking that off and looking for a paint gun.

As you know the vehicle came with one EFI tank (from Tanks Inc.). The previous owner bought one EFI tank and pump from them and left the other tank in factory configuration. He then ran a fuel transfer pump from the other tank to the new EFI tank. In theory you could hit a switch on the dash and it would transfer fuel from the old carb tank to the new EFI tank. Unfortunately none of it worked and I like to do things the right way.

I figured I'd keep that EFI tank and pump and just buy one more to replace the one on the other side. Well, curiosity got the best of me so I opened up the EFI tank that came with it today and removed the fuel pump. Nothing but rust inside of it! The fuel pump had rust flaking off of it. The inside of the tank was rusty as hell! Flakes everywhere! Thank goodness for fuel filters

Anyways, I had to order another EFI tank, pump, and fuel level sender from Tanks, Inc. today. No way I'm putting that tank back on there.

Makes me wonder how all that rust got in there. Maybe it was the ethanol in the gas, or maybe he frequently stored it with little to no fuel in the tank. Either way, I'm glad I looked into that because I almost just left it alone since I figured it was okay.

At the rate this is going next thing you know I'm going to be swapping in an LS7

Glad you found the rust ! , This project could be much much worse , you could be working on the Nissan mini van . Hang in there and have some fun doing it !

 

[Chris]

Glad you found the rust ! , This project could be much much worse , you could be working on the Nissan mini van . Hang in there and have some fun doing it !

The only reason I'm not cursing all of this is because it's actually fun to work on.

That Nissan is nightmare fuel. I won't even work on it myself. I pay someone else to do that for me since I'm not into masochism.

 

[srimes]

Good to know!

What a can of worms I've opened. Now I've decided since the dash is apart I may as well just paint the entire dash white to match the exterior. So it looks like I'll be masking that off and looking for a paint gun.

The front will look good white. If you paint the top of the dash white you may find the glare quite annoying.

 

[Chris]

The front will look good white. If you paint the top of the dash white you may find the glare quite annoying.

Oh no, I am just going to paint the whole under dash white. The top part (the part that is puke green now) will be painted white as well, but it will be covered by the blue dash pad.

The previous owner just didn't paint the upper portion because he was lazy. I know you won't be able to see it with the dash pad, but it's just peace of mind for me knowing it was done right.

Also, the paint on the dash now is rattle can. Someone did a good job with the rattle can to be honest, but it's missing the pearl in the paint on the exterior.

 

[Chris]

Blueprint called me this morning.

They told me that the 396 is based on a late model 86-99 small block and that any flywheel should work as long as it is meant for that block with a one piece rear main seal and externally balanced.

 

[ColoJeep]

Blueprint called me this morning.

They told me that the 396 is based on a late model 86-99 small block and that any flywheel should work as long as it is meant for that block with a one piece rear main seal and externally balanced.

So , what they said in essence is there is no difference in balance between a 86-99 305 and their 389 , " 396 " stroker engine. Good to know .
I guess my builds were old school hot rod , the rotating assembly was balanced to a 1 gram tolerance . This should make things more straightforward for you !

 

[Chris]

So , what they said in essence is there is no difference in balance between a 86-99 305 and their 389 , " 396 " stroker engine. Good to know .
I guess my builds were old school hot rod , the rotating assembly was balanced to a 1 gram tolerance . This should make things more straightforward for you !

Yep, it turns out I need McLeod 460265 and McLeod 560223.

That’s the correct flywheel and counterweights for this swap to work. The flywheel is neutral balanced and I need to install a single counterweight in the correct location on the flywheel.

 

[Rickyd]

Blueprint called me this morning.

They told me that the 396 is based on a late model 86-99 small block and that any flywheel should work as long as it is meant for that block with a one piece rear main seal and externally balanced.

Thats cool. 1 piece rear main and a roller cam if i remember right

 

[Chris]

Quick question guys, McLeod makes two flywheels that will work. Both are identical but one is 22 lbs. and the other is 36 lbs.

Generally a lighter flywheel makes sense, but on something like a truck that doesn't rev very high, I'm thinking the heavier flywheel would be the better option.

Thoughts?

 

[jeepguy03]

I'd opt for the heavier one on a truck, which would be better for low end torque. The lighter one will rev quicker.

 

[Chris]

I'd opt for the heavier one on a truck, which would be better for low end torque. The lighter one will rev quicker.

Yep, that's what I was thinking as well. The lighter one might be nice in a sports car, but being as though this is a truck I think the heavier one is the way to go.

 

[Rickyd]

Quick question guys, McLeod makes two flywheels that will work. Both are identical but one is 22 lbs. and the other is 36 lbs.

Generally a lighter flywheel makes sense, but on something like a truck that doesn't rev very high, I'm thinking the heavier flywheel would be the better option.

Thoughts?

Heavier flywheel will smooth out the firing pulses and give a little more inertia when you let out the clutch. There is probably a lot more on the topic out there

 

[Chris]

Heavier flywheel will smooth out the firing pulses and give a little more inertia when you let out the clutch. There is probably a lot more on the topic out there

It's a mixed bag from the research I've done. I'm going with the heavier flywheel. This isn't a high revving 4-banger, it's a heavy pushrod V8.