Since a 1990 truck has fuel injection, this will be a difficult and expensive task. Everything one the top of the engine will need to be replaced. If it has a throttle body instead of individual injectors the intake manifold, distributor and wiring will all have to be replaced. You will need to decide on what distributor will be used. My suggestion is to come up with another plan unless you have plenty of time and money.
1990
The 1990 Blazer does not have a carburetor.
Though it sits on top of the engine a carburetor is actually a part of the the fuel delivery system. The carburetor is no longer a part of the modern automobile, being replace by the electronic fuel injection system in the late 1980's - early 1990's.
you need the engine, wiring harness, and transmission. All three to make the swap.
To adjust the carburetor float on a 1990 Isuzu pickup, first, remove the carburetor from the engine and detach the float bowl. Check the float height by inverting the carburetor and measuring the distance from the float to the gasket surface; it should typically be around 14-16 mm. If adjustment is needed, bend the float arm gently until the correct height is achieved. Reassemble the carburetor and reinstall it on the engine, ensuring all connections are secure.
Vacuum leak
That F-150 does not have a carburetor. In fact after doing a little research i found that they have not been carburated since around 1990. If it had a carburetor it would be on top of the engine where the throttle body currently is. follow the air filter hose back to the center top part of the engine.
Yes that car has a timing belt
It doesn't have one. The car uses Fuel Injectors. ============================================================================= According to my Chilton's Auto Repair Manual : For a 1990 Mercury Grand Marquis : The 5.0L / 302 cubic inch V8 is fuel injected The 5.8 / 351 has a carburetor ( the 8th " character " of the VIN is a " G " ) The carburetor is located on the top of the engine , below the engine air filter housing
Depends on your engine.. pretty sure the 351 Windsor had gone to fuel injection by that point, so there won't be a carburetor on it. If you have the 7.3 Powerstroke diesel, that still used natural aspiration in that year, and you'll see it on top of the engine.
About 15 mpg on a 1990 Chevrolet suburban.
145 hp with 2-barrel 165 hp with 4-barrel