1966 Frame Questions

[Bradfather]

I have a 1966 C20 Frame/ Long bed. (I assume the C10 frame is the same) I want to drop a 502 BBC into it. What do I have to beef up on this truck frame? I have been seeing just adding some more cross members won't do the trick.

So what needs to be done and where can I buy it?

Thank you.

[padresag]

all c20 are 127" w/base or longbox. so what truck do you have? actually the C20 frame is a little heavier than it c10 counterpart. look under frames in the FAQ section. what are you worried about the frame with a 502 for?
ron

[Bradfather]

Long bed. And Umm, I don't want the frame to twist in half from the HP/torque of a 502.

[padresag]

are you going to race it or a driver. if you are going to go racing, you may as well put that 502 in a brick,
are you going to modify the frame. what trans are you going to use. If you are after that answer you should say what else that you are going to do to it. mentioning what trans that you are going to use is an example. it may mean a c/member removal at that point and the installation of another
ron

[Bradfather]

I'm not racing. But lets say I was going racing! I want the frame to withstand the twisting from the power of the motor. The trans will be a rebuilt TH400. All I want to know is what do I need to do to strengthen the frame so it can withstand the torque from a 502.

Do I need cross members? Do I need a x-frame? Do I need sub-frame connectors? Do I need something else that I have no clue that is out there on the market?

Pretty sure you just can't drop a 502 in a truck without doing some frame modification to withstand the twist.

[padresag]

unless it is an a/trans frame to begin with you will have to remove the crossmember under where the bellhousing was to accommodate th400 and install a rear trans crossmember. they did make an orig rear trans that was pretty stout(Picture below)
those frames are pretty good. all frames will flex. it all depends how one feels about it.There are people that will wear both a belt and suspenders at the same time.
how are you going to transmit that power to the ground. are you going to use 20" wide tires and what type of suspension. depending on those you may have to make alterations to the back frame. people can't guess at what you are going do in order to answer you properly.
this is out of a 66 and note that it bolts to the top and the bottom of the frame
ron

[Bradfather]

I have a posi rear end out of a '71 C10 that I am going to rebuild. Not sure which gears though. Which will be the best ratio?

I am just going to use the stock setup for the rear end with the exception of an adjustable sway bar.

Probably won't use 20" wide tires. Tires will be a little wider than regular.

Will I have to do some beefing up with the rear end? And sorry, I'm new to this car building biz!

[padresag]

. I would go with the newer model a/trans which will have o/drive. means more electrical work the rear end depends on how hard that you are going to be on it. To make sure that it is in good shape I would go through and rebearing the rear end to get rid of any slop. replace all your rear suspension bushings . a C10 frame should give you know problems
ron

[Captainfab]

You really don't have to do much of anything to these truck frames. They are not weak by any means. The frames are basically the same from '63-'87. Frame twist is not going to be a huge issue unless you are running some wide/sticky rear tires. Installing a big block in these trucks is nothing new, it has been done many times. I installed one in my '66 Suburban 24 years ago. If you are overly concerned about it, check out the Racing and High Performance section of this forum and see what guys are doing with the trucks they are racing.

[Bradfather]

Originally Posted by padresag

unless it is an a/trans frame to begin with you will have to remove the crossmember under where the bellhousing was to accommodate th400 and install a rear trans crossmember. they did make an orig rear trans that was pretty stout(Picture below)
those frames are pretty good. all frames will flex. it all depends how one feels about it.There are people that will wear both a belt and suspenders at the same time.
how are you going to transmit that power to the ground. are you going to use 20" wide tires and what type of suspension. depending on those you may have to make alterations to the back frame. people can't guess at what you are going do in order to answer you properly.
this is out of a 66 and note that it bolts to the top and the bottom of the frame
ron

I have that similar thing. So you want me to remove this (1st picture) and move it backwards? To the next set of holes after the cab mount (2nd picture)?

[padresag]

that is a totally different crossmember than what I showed you. that is the one that you will have to remove if you are going for an a/trans.
is this the frame for your truck or another. what is your truck?
another view of that a/t c/member

ron

[Bradfather]

Yes. This is my Chevy C20 frame/truck. That is the only cross member I have on this frame for the trans. Pic is of another angle.

[padresag]

that is not a transmission crossmember. that is a rear engine crossmember
ron

[Bradfather]

Lol. Thanks for the help dude. Obviously you no nothing about anything here in this thread!! Obviously I unbolted the tranny from this crossmember. The tranny just doesn't sit in thin air dude!!

Have a good day!.

[Bradfather]

Sorry. This is so frustrating!!

So if that is a rear engine cross member where is the cross member like yours then? I guess my truck didn't come with one! Where can I buy one? Can I buy the tubular ones like from Jegs or Summit? Would those work?

And if I buy a tubular one or one like yours will I have to remove the "rear motor cross member?

Thanks

[padresag]

Originally Posted by Bradfather

Lol. Thanks for the help dude. Obviously you no nothing about anything here in this thread!! Obviously I unbolted the tranny from this crossmember. The tranny just doesn't sit in thin air dude!!

Have a good day!.

the name is not dude.
the transmission in that truck was suspended in mid air. it was bolted onto the back of the b/housing which is mounted to that crossmember which since at least 1932 has been called the rear eng mount
and I will have a good day
ron

[padresag]

Originally Posted by Bradfather

Sorry. This is so frustrating!!

So if that is a rear engine cross member where is the cross member like yours then? I guess my truck didn't come with one! Where can I buy one? Can I buy the tubular ones like from Jegs or Summit? Would those work?

And if I buy a tubular one or one like yours will I have to remove the "rear motor cross member?

Thanks

as I explained earlier
unless it is an a/trans frame to begin with you will have to remove the crossmember under where the bellhousing was to accommodate th400 and install a rear trans crossmember. they did make an orig rear trans that was pretty stout(Picture below)
. the crossmember that is there is for manual trans. if you are to install an a/trans, you will have to remove it. you will then have to find and install a rear trans crossmember whether orig style or aftermarket or out of a later model truck (http://www.persh.org/pickup/700R4.htm) whether it is a th400, 700r4 or later will all use the same crossmember
If you said at the start that you had a 66 C20 it would have made it simpler. you just said a frame. there are guys that get another frame to work on while they are still driving their trucks or whatever. that is why I asked what you had for a truck. it is easier to define what you actually have at the start and say all what you want to do to it. then others will understand a lot easier.
I am sending you a PM
ron