350 Upgrade

[bcg88]

I am looking to have a little fun with my 69 88 convertible. I want to boost the HP and here is what I am considering:

The engine is stock (2BBL) with the only upgrade being Flowmaster dual exhausts.
I am looking to add a cam/intake/carb combo to boost HP. Instead of the standard Performer route I was considering a Offenhauser dual quad intake, a pair of new 4BBLs and a cam.

Thoughts? Concerns?

Anyone have any experience with this intake. I am still trying to make sure it fits under the stock hood. It is a low rise model.

Any recommendations on carbs or cam?

[Pinner]

The dual 4 intake would make an impresive addition, but you may be dissapointed in the expense/hp ratio. Punch the motor out, boost the compression, cam, roller rockers, good performer intake and 4bbl. Just my opinion. Pinner

[telli_tell]

NEVER forget... if you are going to put bigger cam and change the top end set up. Don't leave out the valve springs and other components if you want your motor to last! Once you go with a big cam on a stock engine... alot of things need to be upgraded.

[joe_padavano]

Originally Posted by bcg88

I am looking to have a little fun with my 69 88 convertible. I want to boost the HP and here is what I am considering:

The engine is stock (2BBL) with the only upgrade being Flowmaster dual exhausts.
I am looking to add a cam/intake/carb combo to boost HP. Instead of the standard Performer route I was considering a Offenhauser dual quad intake, a pair of new 4BBLs and a cam.

Thoughts? Concerns?

Anyone have any experience with this intake. I am still trying to make sure it fits under the stock hood. It is a low rise model.

Any recommendations on carbs or cam?

This is a complete waste of money. At 6,000 RPM, that 350 won't even fully use a single 4bbl carb. In addition, the Offy dual quad intake is a single plane if I recall, which will further kill any low RPM torque. Get a Performer or Performer RPM and either a properly built Qjet or an Edelbrock (Carter) carb. Get a good set of headers and a properly matched cam. Simply throwing together mismatched parts because the look cool is a good may to make the car run worse than before.

[CreekBandDad]

Joe,

What do you suggest for a '68 360 4bbl carb that currently has the stock manifold and a Holley 650 on it? Do they make a Carter or otherwise with a thermostat chock or should I go with an electrical one? Manifold suggestion? Stock or otherwise? Currently a Jeyaway and 2:78 rear gears. I may change those out if I can find the pieces/parts to do it rigth as I have the center console shift.

[joe_padavano]

Originally Posted by CreekBandDad

Joe,

What do you suggest for a '68 360 4bbl carb that currently has the stock manifold and a Holley 650 on it? Do they make a Carter or otherwise with a thermostat chock or should I go with an electrical one? Manifold suggestion? Stock or otherwise? Currently a Jeyaway and 2:78 rear gears. I may change those out if I can find the pieces/parts to do it rigth as I have the center console shift.

There are some good aftermarket intakes. The Performer is good for heavy cars with low numerical axles like yours. The Performer RPM is designed for a higher RPM range and gives up a little low RPM torque as a result. Depends on what you plan to do with the car. I see used Performers selling in the $80 - $125 range all day long. Personally I'll buy a crusty one cheap and have it bead blasted. Just be sure to look for cracks and stripped threads, though a helicoil fixes the threads no problem.

Pretty much all aftermarket carbs use an electric choke. Keep in mind that this IS a thermostatic choke, it just uses an electric heating element to heat the bimetallic spring instead of hot air from the engine. I've had very good results with electric chokes and I usually retrofit them to my Qjets anyway. Just be sure that power to the choke is switched using an oil pressure switch so the choke doesn't start heating until the engine is running. Borg Warner sells an aftermarket electric choke conversion that includes a thermocouple that actually powers the choke element based on engine temp. I've had one of these on my 70 W-30 for over a decade with no problems.

The Edelbrock carb is the old Carter AFB. While I personally prefer the Qjet, I've also had good results with the Carter. Pretty easy to tune. I have not had any luck running Holley carbs on the street. They are great W.O.T. carbs but there always seems to be a flat spot in street use.

Good luck,

Joe P