Engine swap From 250 6 cylinder To 350 sbc

[Ken B]

well I know more now than i did a few hours ago.....thanks
Guessing If i just start pulling stuff apart it will all become apparent. pull carb, empty fluids, pull radiator, and work my way down and back.....lil chicken ****. I will get to the point where I have 2 dismantled trucks....and that bench seat aint comfortable to sleep on.....

 

[Ken B]

question......doing this swap I am pairing the 350 with an auto trans, it was originally paired with a 4 sp manual. I was wondering can a radiator shop add the fittings needed for cooling lines to the radiator?

 

[Memaloose]

Install an aftermarket external transmission fluid cooler, it will be better anyway.

 

[Ken B]

Thanks
I can completely understand in AZ needing the best cooling set up.

 

[Bextreme04]

Thanks
I can completely understand in AZ needing the best cooling set up.

I would be careful doing that with you being in Indiana... the trans will have a hard time coming up to temp when the outside temperature is below zero. The 350 trucks with an auto trans didn't just have the trans cooler in the tank, they were also bigger radiators. I would try to source the right radiator and fan shroud, as well as having an external cooler. Your trans(and engine) will thank you. I have a complete original radiator and fan shroud for a 350 with auto trans, but I'm pretty far away from you.

 

[Ken B]

good to know thanks.....i was just looking at keeping stock rad.
not against the aluminum but .....
my old rad, for the 250 6cyl is probably too small for the 350. It had the cooling lines running thru the rad.

 

[Ken B]

Is it for sale?

 

[Bextreme04]

Is it for sale?

Mine is the bigger 4-core. It needs to have the drivers side tank re-sealed(it held coolant but had a weeping leak from the inlet) and shipping from Oregon would probably make it not worth shipping. I'm putting a bigger 1997 K2500 454 radiator and dual electric fans on mine, which is why its all removed now.

 

[Ken B]

Gotcha.
Thanks
I found an aluminum radiator on Jegs for 190ish. Gonna research that.
I have 2 old school rads. But if they won't get the job done. Gotta go new I guess...

Its 88 and humid as hell today so its online research day. Cooler....

 

[75gmck25]

I used the Jegs Champion CC161 radiator in my '75 K25 with 350, and it cools really well. I could leave it idling in the driveway with A/C all day in 90-95 degree weather and it would never get above about 200 degrees. Once you start driving it comes down to about 185-190, so I think my fan clutch is a little weak.

Bruce

 

[Ken B]

I saw that model on jegs.
Thanks

 

[RecklessWOT]

I would be careful doing that with you being in Indiana... the trans will have a hard time coming up to temp when the outside temperature is below zero. The 350 trucks with an auto trans didn't just have the trans cooler in the tank, they were also bigger radiators. I would try to source the right radiator and fan shroud, as well as having an external cooler. Your trans(and engine) will thank you. I have a complete original radiator and fan shroud for a 350 with auto trans, but I'm pretty far away from you.

I have an aftermarket transmission cooler in addition to the one in the rad, I live in NH where it gets very cold in the winter, I've never had problems. True it does run pretty cold in the winter, I have a temp gauge for it where the clock should go and on very cold days sometimes it doesn't really peek over 100. But to the best of my knowledge the truck has been set up this way since it was almost new and it's never had transmission trouble. I forget exactly how many miles are on it because I haven't been driving it lately but I wanna say it has somewhere in the neighborhood of 170K on it. If you're worried about the cold you can block off part of the cooler the way diesels do with their radiator in the winter

 

[Bextreme04]

I have an aftermarket transmission cooler in addition to the one in the rad, I live in NH where it gets very cold in the winter, I've never had problems. True it does run pretty cold in the winter, I have a temp gauge for it where the clock should go and on very cold days sometimes it doesn't really peek over 100. But to the best of my knowledge the truck has been set up this way since it was almost new and it's never had transmission trouble. I forget exactly how many miles are on it because I haven't been driving it lately but I wanna say it has somewhere in the neighborhood of 170K on it. If you're worried about the cold you can block off part of the cooler the way diesels do with their radiator in the winter

My comment was in response to the comment about only installing an external cooler instead of getting an in-radiator setup. I was trying to point out that there are downsides to doing that if you live in a cold climate as the radiator cooler will actually warm the trans fluid in cold weather, which is what you want. I always recommend both a radiator cooler and an external cooler if you are going to tow or haul anything or live in a climate where you have hills or mountains and see temps above 90 degrees. The bare minimum is a radiator cooler though, an external cooler should only be in addition to a radiator cooler unless you live somewhere that never gets below 50 degrees or so.

 

[RecklessWOT]

My comment was in response to the comment about only installing an external cooler instead of getting an in-radiator setup. I was trying to point out that there are downsides to doing that if you live in a cold climate as the radiator cooler will actually warm the trans fluid in cold weather, which is what you want. I always recommend both a radiator cooler and an external cooler if you are going to tow or haul anything or live in a climate where you have hills or mountains and see temps above 90 degrees. The bare minimum is a radiator cooler though, an external cooler should only be in addition to a radiator cooler unless you live somewhere that never gets below 50 degrees or so.

Gotcha. I see what you mean now, and yes I agree. Sorry, I thought you were just speaking out against aftermarket coolers

 

[Ken B]

got a few days off coming up might try and tackle this....got radiator out and oil drained. hoping i can unbolt at bellhousing. I am not using trans, would prefer to leave as much as I can in place.