best mod for a stock 390

[colorado71]

Wanted some opinions on the best modification for a stock 390 4v it already has an electroinic distributor. and a carter 750 4v. everything else is stock. aluminum intake? hedders?

[1971ford]

There is a lot of debate whether or not stock exhaust manifolds or headers are better so i would just leave your manifolds for now.
You could swap over to a Edelbrock performer intake though, it is a dual plane aluminum intake that will save you a million pounds up front. I was told they are most simliar to our stock intakes, but of course they are a whole lot lighter.

[70_F100]

First question:

Are you ABSOLUTELY SURE it's a 390?

Have you measured the stroke, or are you just going by what you were told by the PO?

[Jarred Hodges]

I would go with headers. I believe that the factory manifolds were very restrictive

[convincor]

the factory type 4V intake will flow better than a Performer. If you going to bother with intake at least go to a Performer RPM.
Header won't do much for you at this point except make more noise so you think your going faster.
Best bang for buck in my opinion would be a cam change to something like a Comp 260H, XE262, or 268H.

[colorado71]

First question:

Are you ABSOLUTELY SURE it's a 390?

Have you measured the stroke, or are you just going by what you were told by the PO?

yep, i know the last owner, unless the machine shop that built the engine b.s.'d him its a 390. the truck origionally came with a 360.

[colorado71]

Is there a certian year of head thats better than others?

[dustman_stx]

the factory type 4V intake will flow better than a Performer. If you going to bother with intake at least go to a Performer RPM.
Header won't do much for you at this point except make more noise so you think your going faster.
Best bang for buck in my opinion would be a cam change to something like a Comp 260H, XE262, or 268H.

I agree with the cam change, but IMHO you are wasting your time doing a lot of intake upgrades without doing exhaust upgrades, i.e. exhaust and headers. You have to have flow through and engine, meaning you have to look at it as a system. If you really want good performance, get it flowing in and out.

[sideoilerfe]

Header won't do much for you at this point except make more noise so you think your going faster.
Best bang for buck in my opinion would be a cam change to something like a Comp 260H, XE262, or 268H.

I agree with convincor on the exhaust. I've put headers on a 352 and a 390 that both ran great and nothing changed. I'd go with a cam change first.

[hotrodfeguy]

I would prolly drop to a 600cfm size carb, then look for a performer intake, maybe step up to a RPM if you are going to make more porwer later. Survival motorsports has a nice truck grind for a cam. That would be my picks for a stock engine.

[Redcap]

Cam and intake.

[DuckRyder]

Headers and dual exhaust if it is a "car" 390 4v.

The factory 4v intake is at least as good as a performer in every respect except weight.

If it has stock exhaust manifolds the outlets may be as small as 2".

If its a truck 390, then probably nothing is going to do much until you get the compression up...

[sideoilerfe]

The factory 4v intake is at least as good as a performer in every respect except weight.

If it has stock exhaust manifolds the outlets may be as small as 2".

Most are 2 1/4" . I've had 5 and they've all been 2 1/4".

If its a truck 390, then probably nothing is going to do much until you get the compression up...

I agree.