I thought I'd pass along any useful info on the 4200 as I progress the install into my '51 GMC where the now departed 292 used to live... This will be a running dialog as I find and fix issues.
The GMC has a '78 nova front clip installed so its a front steer chassis.
- the drag link and pitman arm interfere with the AC compressor
- since the 4200 is a deep skirt block the oil pan flange is about 4" lower than the 292 so the CL of the crank is much higher that the 292 (roughly 5" once I get the mounts made I update the dim).
- in '98 GM redesigned the 4L60E to use a longer input shaft and stator support - its about 30mm longer, so the 4200 needs a late model trans to work or these 2 parts changed out. The bellhousing is also deeper by 30mm.
- the distance from the back of the head to the bellhousing flange on the block is shorter by ~3" than the 292 so even with the extra 30mm of bellhousing the back of the head is closer to the firewall than the 292. I had to move the transmission mount forward about 1" so the back of the head had 1/4" clearance. The 292 had about 1" clearance to the firewall.
- the RH engine mount bolt pattern is different than the LH engine mount bolt pattern ( the LH is symetrical. The RH is not the top rear bolt is located lower by about 3/4".
- the oil filter is really close to the drag link need to verify.
