bgl0b6 Posted February 3, 2012 Share Posted February 3, 2012 Thanks for any help you may be able to give me.I am going to install a '71 402 in my '71.The car when I bought it had a '79 305 with a 200 metric trans.The 402 was in a '71 Impala,with a 400 Turbo.The frame motor mounts in the Impala 402 were about an inch higher than the mounts on the Monte Carlo,should I leave the shorter mounts in the Monte Carlo or use the higher mounts from the Impala?Also the trans cross member in the Monte Carlo is a 2 bolt mount and the member is mounted in the farthest holes forward position,the 400 has a 1 bolt trans mount and is considerably longer than the 200 was.Can I use the 2 bolt mount off the 200 trans,and will I have to refabricate the cross member to get it far enough back to mount it in the car for the 400?I see there are several sets of holes to relocate the cross member,just wondering if they will go back far enough to allow the 400.I am sure this type of change has been done many times and it is Chevy to Chevy so I assume it will be no problems but asking first,Thanks....Mike Quote Link to comment Share on other sites More sharing options...
bobsmc Posted February 3, 2012 Share Posted February 3, 2012 leave the frame mounts on the monte.they are the same fom big block to small block the holes in the frame are predrilled for the 400.just slide the crossmember back and you should be good. a new trans mount is very inexpensive so i would go with the correct new one . ps welcome to the club! bob Quote Link to comment Share on other sites More sharing options...
bgl0b6 Posted February 3, 2012 Author Share Posted February 3, 2012 Thanks Bob,I was pretty sure I knew that was right but thought I'd question that all for sure first.I am sure I will run into other things as I go but those were my first concern.Its nice to have a place like this site to be able to get the answers from people who have been here already.Its been 30 years since I done much of this type of game....Mike (My midlife crisis) Quote Link to comment Share on other sites More sharing options...
bgl0b6 Posted February 8, 2012 Author Share Posted February 8, 2012 I put it in the car Friday night,dropped right in nicely,lined everything up,now going to pull it back out and finish detailing the firewall forward and reinstall in a week or 2.Thanks ...Mike Quote Link to comment Share on other sites More sharing options...
72-CLASSIC_RIDE Posted February 8, 2012 Share Posted February 8, 2012 It is possible that your drive line length may need to be shortened with this conversion also. When I went from the 350 CI / 350 Transmission to the 402 / 400, the driveline needed to be shorter and I think the rear axle yoke was also different if I remember correctly. Â Doug Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted February 8, 2012 Share Posted February 8, 2012 you will need another driveshaft Quote Link to comment Share on other sites More sharing options...
bgl0b6 Posted February 8, 2012 Author Share Posted February 8, 2012 Is it just a shorter drive shaft that I will need or a different type of drive shaft.I have a yoke from the Impala that I took off the drive shaft from the 400,was going to have mine shortened to fit with the yoke.....Mike Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted February 8, 2012 Share Posted February 8, 2012 I think that the 400 yoke used a different size u joint. I think it is a 1330 series joint and the th350 is a 1310 series joint. There may be a adapter joint. A good drive shaft shop should be able to steer you in the right direction. Quote Link to comment Share on other sites More sharing options...
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