Cad 331 TBI ?

[uncabob]

I have a 52 Caddy with a rebuilt 331 engine and trans. Would like to go with TBI. Has anyone gone this route? I never want to overhaul another carb.

[dave w]

Updating the 331 to TBI is possible.

The real heartbeat of the conversion will be the distributor modification. Maybe your 331 points distributor can be converted for TBI. Check this link: http://www.davessmallbodyheis.com/ for information and pricing to have the 331 points distributor modified for TBI.

dave w

[uncabob]

Updating the 331 to TBI is possible.

The real heartbeat of the conversion will be the distributor modification. Maybe your 331 points distributor can be converted for TBI. Check this link: http://www.davessmallbodyheis.com/ for information and pricing to have the 331 points distributor modified for TBI.

dave w

Thanks Dave. I'll give him a try. Any suggestions for an ECM? I think I,d like to go with the dual TBs used in trucks.
Bob

[Six_Shooter]

If you mean the 2 bbl throttle bodies, then any of the TBI ECMs will be good. The simple conversion will be to use a '7747, while a more involved, but possibly more rewarding result would be to use the '7427 PCM.

[uncabob]

Thanks Six_Shooter - Do you know of a thread where the differences may be explained?
Bob

[Six_Shooter]

If you search up "7747 to 7427 swap" or similar search parameters you should be able to get a feel for the differences, and why some people prefer one over the other.

[dave w]

The '7747 is about as simple as TBI can be, and very affordable. Possibly the '7747 is the best choice for the first ever EFI project. Many gearhead-efi.com members had a '7747 TBI as their first EFI experience.

The '7427 is a better, possibly the best, TBI computer. The '7427 is a slightly more expensive TBI system because a Vehicle Speed Sensor (VSS) is required to take full advantage of what makes the '7427 a better computer than the '7747.

Generally, the aftermarket has better support (plug-n-play harness) for the '7747.

Maybe the option of upgrading to the '7427 a year or two after getting up-to-speed with the '7747 is a good plan?

dave w

[Six_Shooter]

My experience is that the '7747 greatly responds to the addition of a VSS as well.

[uncabob]

My experience is that the '7747 greatly responds to the addition of a VSS as well.

I agree. I just put the painless VSS in my 49 Jimmie that has the 7747 that Dave W helped me with.
Any one know if there is an intake made that would be a fit up for the 331?
Or should I make an adapter for a throttle body and machine the 4bbl manifold to fit?

[uncabob]

The '7747 is about as simple as TBI can be, and very affordable. Possibly the '7747 is the best choice for the first ever EFI project. Many gearhead-efi.com members had a '7747 TBI as their first EFI experience.

The '7427 is a better, possibly the best, TBI computer. The '7427 is a slightly more expensive TBI system because a Vehicle Speed Sensor (VSS) is required to take full advantage of what makes the '7427 a better computer than the '7747.

Generally, the aftermarket has better support (plug-n-play harness) for the '7747.

Maybe the option of upgrading to the '7427 a year or two after getting up-to-speed with the '7747 is a good plan?

dave w

That sounds like the best plan for me (a newby) as the 7747 is a bit familiar to me. Just downloaded Tunerpro RT and have to learn that now.
Thanks for the advice from all of you folks.
Bob

[dave w]

Should I make an adapter for a throttle body and machine the 4bbl manifold to fit?

I would make a custom throttle body Adapter Plate to mount Between the 331 intake manifold and throttle body.

dave w

[uncabob]

Thanks Dave:
That is probably the easiest and quickest way to go. Sent a query to Dave Ray about the distributor yesterday.
Bob

[Byron]

Adapters can be found at CFM Technologies
http://marine-performance-parts.com/...cessories.aspx

[uncabob]

Thanks Byron I'll try them.