FWD vs RWD VQ35DE Differences

Member Credit: pmohr

To try to cut down on the ‘can I use a 350z motor in my car‘, or ‘why can’t I use a G35 or FX35 or (etc) motor for my swap?‘ type of questions. The following pictures all have the blocks aligned in basically the same exact way for ease of comparison).

RWD Block (350z, FX35, G35, any RWD VQ35DE platform)
FWD Block (Maxima, Altima, Quest, any FWD VQ35DE platform)
Mounting Comparison

• RWD:
  • Large bolt pattern, maybe 8″x5″ (from memory, definitely not accurate)
  • Mount cast positioned towards the timing cover
• FWD:
  • Small bolt pattern, maybe 4″ square (from memory, definitely not accurate)
  • Mount cast positioned towards the end of the block

Accessory/Manifold comparison

• RWD:
  • Exhaust manifolds/headers curve backwards, away from the motor mounts
  • Accessory mounting points are located vertically along the front edge of the block (these are for the AC compressor, IIRC)
• FWD:
  • Exhaust manifolds/headers head straight down, motor mount is offset and doesn’t get in the way
  • Accessory mounting points are located horizontally along the lower edge of the block

Here’s two side-by-side pics (blocks are aligned in the same position, however the FWD block has torque plates ‘installed’):

Left side

Right side (crappy pic, but you get the point)
Basically, you can definitely use the RWD block in a FWD design, it would just require re-engineering of a lot of things. Not even minor things, but motor mounts, headers/exhaust manifolds, etc.

To use a RWD block in a FWD chassis

• Custom motor mounts that extended towards the trans to utilize the center crossmember. Would most likely be weaker than the stock FWD mounts (on the FWD block) unless you braced the hell out of them.
• Custom headers made to stretch around the custom motor mounts made above – as you can see the RWD mounts are just plain in the way of any sort of manifold that comes straight down.
• Custom mounting brackets for all of the accessories, or try to customize the RWD accessories/mounting rails to work

Benefits of using a RWD block in a FWD chassis (assuming it will ever be done, not likely)

• Turbo manifolds could go directly over to the driver’s side without the typical FWD mount interference
• Engines may be easier to find
• Possible ability to use the revup engine (with all associated electronics of course)