Hi all. Any good ideas as to the major points and common "oops" experienced when performing a small block to big block swap? (or where this info is posted) --Engine bay has been clean/empty for over 1.5 years. Old bolts were tagged and a number of pictures taken when I pulled the original motor. A "for instance". I purchased the aluminum 455 frame pads. Do they bolt to the same location as the 350 pads? At least one hole looks to be in a different location. The project is a bracket racer ('70 GS). So no AC or any extra stuff going in. It looks to be relatively clear cut, but I'd like to be sure. Another "Q". Does anyone fabricate a solid front mount to tie down the block/heads to the frame? Thanks in advance for looking through my Qs/ John
John, check this post. I will start another when I get the block back from the shop :beer http://www.v8buick.com/showthread.php?s=&threadid=7109 Remember you can use the search feature and find lots of stuff.
One thing I found on my swap was to make sure the headers are in place when installing the motor. The first time I put it in I did the headers after it was in place. I thought I was never going to get the pass side in! Practically had to remove the motor to get it to clear!. The second time it was installed I still had the headers bolted to the exhaust system and it was a breeze.I am running Poston headers so other types may be different. Also if you are going to run tall valve covers it is a whole lot easier to install if you leave the valve covers off until it is in place, especially if you have A/C. I found that out the hard way after cracking the A/C housing the first time around. Hope this helps you some. Brian
Here's what I know: the 350 and 455 frame pads are in different locations. Seems like all the holes are drilled for either, though. Just a matter of using the right pad and combination of holes. I just did the Poston headers install myself last week. Right after pulling the engine and reinstalling it again (long story). On the left (drivers side), I found I had to cut the piece of flange out between #5 and #7 so I could use the dipstick. I also unbolted the brake proportioning valve bracket so I could get just a little more wiggle room with the brake lines. All the brake stuff clears when the header is in position. I also temporarily removed the TH400 shift linkage to get it out of the way. On the passenger (right) side, there are two heat shields that must be removed. One bolts to the block just below the deck surface, other is on the motor mount. I also had removed the transmission cooler lines and the vacuum modulator line. I have a tubing bender and flare tool, so I bought 5/16" stock and fabricated new cooling lines. To do this, I had the front end of the car up so high that gas was leaking out of the filler neck into a drain pan. I used TA Performance 12-point 3/8" header bolts and starter heat shield to make the job complete. There is NO WAY you can use the Poston-supplied 6-point 7/16" header bolts on the bottom middle holes. Anyway, the Poston headers fit OK without grinding the control arms or getting out your least favorite socket and a BFH to make clearance 'dings' on the tubing.
With my T/A headers, I found the easiest way to install the engine without a lift or pit was, for me, to loosely bolt the motor mounts to the pads, then lower the engine onto them..I found I could sneak a wrench in between the oil pan and crossmember easily if I was laying in the right position, and while under there, I could reach the mount holes with a drift pin, so I had a helper raise/lower the engine on the engine lift slightly untill I could line them up. Without a helper, I found I could get three bolts in...but not all four! I remember thinking that if I had not put the heads on yet, I could probably have done it without removing the mounts from the engine and bolting them to the pads, at the time.ou: The fit of the T/A headers is very good looking, neat and snug with the heads, but I found that the tranny coolant lines are very close to the headers, too close if you ask me, and the starter motor without a heat sheild bolted in fine, but with one....a struggle, but possible. The driver's side needed a whack for the steering shaft, and if you install the #7's header bolts first, it might be smart. The toughest one to do is there, so you won't have the unpleasant experience of having the project get harder as you go along!
