I have a 1990 toyota pickup DLX ext cab V6 5-speed

check the width of the chassis rails for starters . If the same width then check the cab mount distances . With 9 years between chassis I would think that the chassis will be different

Change the speed sensor if you have the electronic speedometer. If you have a cable driven speedometer, buy a new cable, and replace.

Sounds like it might be a bad fuel pump, check fuel pressure should be 2.8-4.3 psi

Sounds like ignition timing if it only happens when you accelerate

The Manufacturer's recommended tire size and inflation decal should be in the door jamb below the latching mechanism on the driver's side door, but if it is not there, 29-30psi front 32-34psi rear. You can go with 32psi at all four corners. That is the pressure i run in my '85 Xtra Cab DLX and it works great.

Hope this helps,
matt

No difference in transmissions at all between single cab and extra cab.

after exhausting your local salvage yards, make sure to ask to find one on satellite, you might try transmissions.com. to find a good guaranteed unit .

james ray

if transmisson auto check fluid levels ok

have u checked to see if theres any gas in the fuel tank

Speedo cable?