BBC for my long box 67, what problems am I facing?

[67 fleet side]

Hey guys

I've recently been considering putting a big block in my long box 67 GMC. The truck was originally equipped with a 283. What kind of problems am I going to face? Will I require a completely new cross member up front? With adding that much torque is there better pilot bearings because the stock set up seems a little weak to me.

[ecgate]

Your biggest hurdle is having to find 68-71 bbc engine mounts and stands. I run a fairly built 402 and my pilot bearing seems to be fine. You don't need a new cross member if you a 2wd truck. If its a 4x4 I think you would be opening a can of worms that will give you headaches for days on end. You''ll be fine as long as you have the correct motor mounts and stands.

[Shyguy]

When we put a '74 454 in my '67 that has a '68 -'72 frame we used the stands and motor mounts that were in the '74 truck. My truck has a Sm-465 tranny.

[davepl]

Engine stands. And depending on the year, mounts. The '70 mounts for example are not available at autoparts stores and run you $200 or more for repops with the wrong bolts (grrr).

Generally the toughest part is all the accessories, mounts, brackets, and so on. Much easier if you've got a donor vehicle that has all of that to start with. Starting with just a motor would be no fun. Been there, done that, wouldn't do it again.

[67 fleet side]

Thanks for the replies guys. Clearly my biggest problem is stands and mounts. What about clearances for headers? I already have a pretty snug fit with long tubes on my small block. Would it just be as simple as switching to shorties?

[1970 CST Short Wide]

I used the 72 mounts in my 70 and have long tube headers that fit perfect with no issues. I'm trying to remember who made them (sorry bout that) I know I bought them from Jegs and they are 1 3/4 primary tube, being small may be why they fit so good!!
When I did my swap I started with just a 454 and started accumulating parts slowly until I had what I needed. I bought all the accessory parts from guy’s right here. Keep an eye on the parts board there are some good deals if you wait and watch. Good Luck with your build

[Sheetaki]

You may run into header clearance issues, as in '67 the frame by the engine was wider. In '68 when they offered the big blocks, they cut a clearance into the frame, so I imagine you'll have to do something similar. I discovered this the hard way in my '67
http://67-72chevytrucks.com/vboard/s...24#post6421024

[alltexan]

I bought these and put a 396 in my 72 with 1 7/8 tube headers and had no problem. Fit like a glove. But they aren't stock ...thats the only problem if you wanna stay original http://www.ebay.com/itm/1963-72-CHEV...c58bthat's the only problem

[67ctener]

I cut my frame rails to match 68+ for the header/manifold clearance

[Fitz]

Originally Posted by 67 fleet side

Hey guys

I've recently been considering putting a big block in my long box 67 GMC. The truck was originally equipped with a 283. What kind of problems am I going to face? Will I require a completely new cross member up front? With adding that much torque is there better pilot bearings because the stock set up seems a little weak to me.

Sounds like lots of guys cut their frame to get the headers in but you really don't have to do that. Just get the right engine stands and a set of headers that fit. Mine are Sanderson long tube block huggers and I don't think there's any doubt that the engine is a big block. It dropped right into my 67 Stepside with the headers!.

The correct BB engine stands are getting a bit scarce so be prepared to pay a bit. there are several vendors on this board the have them and they won't ask for your first-born to pay for them.