Astrovan Engine Pictures
The L31 swap


This page is the start of an L31 swap into a 1986 Astro
with 97K miles on it. I purchased the production L31
with the hopes of doing a 4.3Z to a L31 swap adding
more than 100 more HP under the hood.
The engine swap was completed March 2004


L31 Engine fresh, still in the crate. Kind of dusty isn't it.



No extra charge for the flywheel, manifolds and wiring.
Thank you Generous Motors!


This thing says Astro all over it,
Ok so maybe it says it on the inside.

I removed the factory intake and installed the TBI intake.


TBI intake installed.


Test fitting TBI and fuel lines

Fuel lines need to be rerouted some


Fuel lines reworked and distributor installed

Fuel lines- view from the top

Mounting cruise module and accelerator brackets


Side view

View from inside, engine removed

4.3 in sub-frame


Close up of rear of 4.3 before disassembly

4.3 Intake before disassembly

Front of TBI on 4.3

A/C mounting 4.3

V8 mounted in sub-frame. Body ready to be lowered

Same as above, close up

V8 mounted in sub-frame. Front view

Body lowered onto sub-frame,
nice fit.

Body lowered down and mounted to sub-frame

Checking for fan clearance with radiator

Side view of fan blade and radiator

Front view with radiator installed

Fan shroud modified for the 350


Fan shroud modified for the 350

Fan shroud modified for the 350

Fan shroud modified for the 350


Lower fan shroud



LH engine mounting bracket,
can someone please clean the steering linkage?

Rh engine mounting bracket

Left side of cross over pipe

Right side of cross over pipe

Catalytic converter & muffler

Catalytic converter

This will be the Astro's second engine swap. The first was 3 years ago.

That job went fairly smooth. Check it out.

This time its going to take a little bit more patients as we will have to do some modifications to drop this L31 into place.

This is how the project is going so far.
We have a Donor vehicle for spare
parts and when we are ready for the
swap we can just slam the new
sub-frame w/engine into
the Pahh Van*
as my son calls it


*Pahh... as in that's what it does currently when you step on the gas. Hmm
not for much longer.