need some big block swap help

[fast_dev]

hey guys, swapping out the old 283/3 speed combo in my 70 to a 402 with a car 4 speed. keeping the stock bell housing so the problem im having is the mounts don't line up with the crossmember. i have the correct big block motor mounts so i know thats not the problem, do i just move the crossmember? i wouldn't think it would be riveted in different locations for different engine combos. also if i move it what size bolts do i use to replace the rivets? Thanks, Devin

[Tx Firefighter]

By far the easiest way is to get an automatic trans crossmember and mount it under the tailhousing of the 4 speed transmission. There will be two threaded holes underneath the back of the trans to do this with. The reason the holes are there is that the cars used a rear transmission and mount rather than the bellhousing mount like trucks did. You will have to remove the stock trans crossmember though, which can be a chore sometimes.

[fast_dev]

what would the stock setup be with a big block and a stick? same crossmember just in a different location? i got the stock crossmember out, but dont have one from an auto truck so im just going to try to use what i have. i know this may sound weird but im trying to build this from parts i have with as little cash put into it as possible, so far i got 12 bucks invested for a new throwout bearing, lol. Thanks, Devin

[70rs/ss]

With a stock big block placement is the mounts are in the forward holes on the frame rail and the tranny crossmember bolts where ever it lays (put it in and slide it under the tranny and use the holes that line up and drill the ones that do not. It is easy, and as mentioned about the auto crossmember is easier, but it can be done with the manual crossmember, just with more labor and gentle curse words and did I mention BFH (big f***ing hammer!) Three times the labor or a little more money, you decide.

[crazy longhorn]

The crossmember that you have wont work with the BB.....there were 3 different bell crossmembers(depnding on eng ), so you cant just slide them. The best route would be like TX firefighter said.....just chop out the bell crossmember, & use an auto crossmember(you can probably get one for around $25). best of luck.... L

[70rs/ss]

Here I go getting confused again. Does the 3-speed mount under the bell housing like the sm465? If it does, then you will need a new crossmember. The car four-speed you have mounts like an auto. I was thinking the 3-speed had a different mount than the 4-speed, and then therefor could be used. OOPS!

[71/454]

Sorry if this is a dumb question, but i'm doing the same thing but with a previously smallblock auto truck. What is the difference between a big and smallblock pivot ball? I assume that is just the ball that bolts to the engine? Also what do you mean when you say bellcrank? I have the conversion stuff from a smalblock granny 4 speed truck. Is that what others refer to as a z-bar? Sorry do not mean to hijack the thread, I just thought I had it figured.