Will an RB Front Crossmember fit on a Mark 1 MGB-GT?

ahdriver · March 30, 2012, 05:57:18 PM

I have a 1967 MGB-GT shell, a couple of SBF engines and a Tremec 3550 laying around, so the decision to do a V8 swap was made. I understand that the RB cars make this swap easier in part to the front crossmember. Will the newer crossmember bolt into the '67 shell? If so, what other issues arise from this conversion? Steering?

rficalora · March 30, 2012, 09:58:54 PM

the crossmember will bolt up, but I think that'd be just one of several changes.. Checkout out posts by Chris Salisbury (cj steak) & Paul Speak's posts on this board. Both have 302's in earlier cars. Chris's is a '67 GT like yours if I recall.

ahdriver · March 31, 2012, 08:24:33 PM

Thanks Rob,

I've been through all the forms, not finding much on any crossmember swaps...I'll keep looking. These forms are a world of knowledge, and I'm constantly bookmarking them. Cutting in to this car is a little scary, never done anything like this to an MG before, or any car for that matter. I've built cars, done big block swaps, but this is different!

rficalora · March 31, 2012, 10:21:38 PM

I think you'd want the RB steering rack to go with the cross member. And that may require the recessed cone where the steering goes through the fire wall. Not sure where Walled Lake is, but look up Ted Lathrop @ www.fastcarsinc.com and Steve Carrick @ www.advanceautowire.com. Both are in MI and have done 302 swaps. And PM Chris; I'm sure he'd be happy to share what he did.

Doc Hopalongfoot · April 01, 2012, 08:11:29 PM

Hi Mark,
I'm in the Royal Oak area and my SBF RB roadster is mostly finished.
Send a PM and you can stop by for a chat sometime.
Marc

djw090 · April 02, 2012, 04:52:39 AM

Of the helpful features on a rubber bumper car I think the cross member is the least valuable. While it results in greater clearance between the sump and the cross member it also raises the cars ride height. Therefore creating clearance by surgery to the chrome bumper cross member may be more desirable.

The cut away bulkheads, additional dishing in the inner wings and forward radiator mounting that you get in late rubber bumper car are of more use.

mgbreis · April 02, 2012, 10:33:58 AM

To follow on David's post, I personally would not want to swap a RB x member into a chrome bumper car. Yes, by doing so you gain clearance between the x member and the hood, but unless I'm mistaken you still have to notch the RB x member. And, by gaining the inch (or more?) of hood to x member clearance, you end up with a raised ride height in the front. Which you don't want. So then what? Lowering springs? Lowered spindles? Any of which is a bigger pain in the butt than just using the chrome bumper x member and notching it appropriately. And on a mk I car, or really any chrome bumper car, the modifications to the firewall and tunnel are a much bigger challenge than working around the chrome bumper x member. As long as you can run an angle grinder with a cut off wheel and a welder you'll be just fine!

Chris Salisbury, who posts over at the mgexperience site as CSTEAK, and also posts here, has a '67 gt converted to SBF. He would be a really good source for you to talk to.

MGBV8 · April 03, 2012, 10:05:08 PM

I'm with David & Ryan. No way would I do that. Find a way to make it work. Heck, I have a CB crossmember I plan to swap into my RB car.

pspeaks · April 04, 2012, 03:53:35 PM

I'm glad to hear all this! I thought I made a mistake using my 72 cross member, not knowing there is a difference, but apparently while being ignorant, did the right thing. Who would have thought :-)

Paul