swaping in a 454 bbc

I am probably going to be swaping a 454 into my 77 chevy k10...it has a 400 sb in it right now but has been giving me so many problems....blow by, loss of compression...and i think think the block might even be cracked because of white smoke out of the pipes. My question is will I be able to just swap in the 454 without any fear of trashing the tranny...I have a th350 w/np 203 t-case. I have read abunch of threads saying that you need to beef up the th350 for people that have 600hp big blocks. But, I am not looking to drag my truck, I just figure if im gunna get another motor I might as well go with a big motor that is gunna sound mean. All I plan on doing is just boring out the block to get whatever lip is there and then just go with a basically stock piston, new gaskets and headers. Will this pretty much stock 454 be alright against my new/stock th350?

Posted by 1977moneypit - 12-04-2004 at 02:25 AMI am probably going to be swaping a 454 into my 77 chevy k10...it has a 400 sb in it right now but has been giving me so many problems....blow by, loss of compression...and i think think the block might even be cracked because of white smoke out of the pipes. My question is will I be able to just swap in the 454 without any fear of trashing the tranny...I have a th350 w/np 203 t-case. I have read abunch of threads saying that you need to beef up the th350 for people that have 600hp big blocks. But, I am not looking to drag my truck, I just figure if im gunna get another motor I might as well go with a big motor that is gunna sound mean. All I plan on doing is just boring out the block to get whatever lip is there and then just go with a basically stock piston, new gaskets and headers. Will this pretty much stock 454 be alright against my new/stock th350?
The TH400 would be much better. Would be alot of work on the conversion process though. The coolor lines, shift linkage, all those things would match up fine. The vacuum modulator is in a different location, but that's no biggie. The overall length of the 400 is greater than the 350.

But for your purpose as you have stated the TH350 would probably be alright. But I surely would not install a stock 350. You want one beefed up with some guts to it. And I just don't mean a shift kit. You need the inside of the tranny beefed up as well. Not just a shift kit with some heavier springs in the valve body. You want things internally done like replacing the rear output shaft thrust washer with a front pump torrington bearing. Also removing every third piston return spring inside of the clutch housings will help to strengthen the trans. I could go on, there a few tricks you learn over the years to try and make em more bullet proof. But for my money the best tranny and possibly the best tranny ever is the TH400. Good luck with your project, sounds really cool. I use to have a Chevy 1 ton dually with a 454 & a TH400 deep pan bolt on yoke. Loved that truck, it was a 2 door not 4 so I could park it in my garage. Never should have sold it. Grrrrrrr@ex-wife
p.s. absolutely run a external trans oil cooler (if you don't have one already) run it inline with a good radiator.

awsome...preeshiate it...
ya, I havent really been working on these things long, per say, but i have been doing it for about the past 4 or 5 years and its one of those things...I just wanted to know everything that I could about what i was working on so I read ALOT of info on them. I know that the SMART thing would be build up the tranny, but 1) when was I ever being smart buying the thing to begin with..lol..and 2) I wish I had the money right now, so Ill just be careful till i can find that special th400...
How much torque difference is there between a 400 sbc and a 454 bbc?
I have seen only around like 50-60 ftlbs difference? Am I wrong?

Posted by 1977moneypit - 12-05-2004 at 06:28 PMawsome...preeshiate it...
ya, I havent really been working on these things long, per say, but i have been doing it for about the past 4 or 5 years and its one of those things...I just wanted to know everything that I could about what i was working on so I read ALOT of info on them. I know that the SMART thing would be build up the tranny, but 1) when was I ever being smart buying the thing to begin with..lol..and 2) I wish I had the money right now, so Ill just be careful till i can find that special th400...
How much torque difference is there between a 400 sbc and a 454 bbc?
I have seen only around like 50-60 ftlbs difference? Am I wrong?
You mean ft. lbs of torque between the two motors? To tell you the truth I'm more of a tranny guy, always have been. But I have been around some motor people in my time. A shop I use to work for we use to build the trans for a class 8 off road racer, Ivan Stewart was the driver, before he left and went with team Toyota. Won the Mint 400 one of the last years they had that race.

The 400 is an awsome small block, that's for sure. But the 454 omg, that sucker could tow a brick house without even break'in a sweat. Luv them 454's. The TH350 will do you good. I don't mean to worry you about it. It's just what I was telling you would be the way I would prefer to set it up if it was my ride. Just don't go crazy with it and the 350 should last with no probs. Least until you can find the nickles and dimes to put yourself together a good TH400, or get that 350 bullet proofed.

All the best bud, keep me informed on how it's go'in k?

You mean ft. lbs of torque between the two motors? To tell you the truth I'm more of a tranny guy, always have been. But I have been around some motor people in my time. A shop I use to work for we use to build the trans for a class 8 off road racer, Ivan Stewart was the driver, before he left and went with team Toyota. Won the Mint 400 one of the last years they had that race.

The 400 is an awsome small block, that's for sure. But the 454 omg, that sucker could tow a brick house without even break'in a sweat. Luv them 454's. The TH350 will do you good. I don't mean to worry you about it. It's just what I was telling you would be the way I would prefer to set it up if it was my ride. Just don't go crazy with it and the 350 should last with no probs. Least until you can find the nickles and dimes to put yourself together a good TH400, or get that 350 bullet proofed.

All the best bud, keep me informed on how it's go'in k?

definately will my friend...I will get the block within about a week and then i guess ill just see what the best deals for pistons are to direct my way as far as boring it out...ya no, nothing like .250" over or nething, just like a.060 bore... but from then on its pedal to the metal so ill keep yall informed and hopefully i wont have too many ????s...