i just recently purchased a delta 88 convertable and i love it. It currently has a 2bbl 425, but i am in a search for a new intake and 4 bbl carb. if anyone knows a good place for a good price let me know. Even if the intake is used will work, but i do want new carb Also want every specialist here opnion on what kind of 4bbl. i have heared that theres vacume and manual. which is better and how much more hp do you gain with performance intake vs stock. I do have pics of my car that i uploaded yesterday. Proud to be an owner of a us made classic muscle car

 

If the car is a factory 2bbl carbed engine it would have come with single exhaust. Converting to true dual exhaust will improve performance greatly. The switch to a 4bbl carb in my opinion will not net much in the way of "seat of pants" get up and go until you reach a higher speed. 4bbl carbs from Holley come with either vac secondaries or mechanical. Vacuum secondarys work well and usually open at the proper time for good performance. Mechanical secondarys can cause a bog in acceleration if operating conditions are not optimum when opened.

 

ok well vacume it is and it does have a custom dual exhaust when i bought it. i have tested it and saw pressure from both.

 

right now when i floor it, there is not that much power and i know alot people are saying that changing the intake and carb is the best option

 

The high compression/use premium fuel only 425 should be pretty responsive. A a stand still it should be able to break a tire loose and get up to speed rather quickly. Possibly a tune-up is in order or the carb is not up to snuff.

 

Now people are giving me different information. Some are saying to use low oct gas with lead additive due to it being an older car. Should i be doing that or just use premium. Should i add lead to the gas?

 

I would use high octane gas, throw some lead substitute or the like in the tank every now and then and drive. Perhaps your timing is retarded a little to run on regular gas to eliminate pinging/pre-ignition. The rebuilt 425 in my Sfire was a high compression engine. I set ignition timing to stock and used the guidelines I just mentioned and had no problems.

 

thank you guys for all the help. Does anyone recommend a specific intake for the 425. Or would a stock intake and 4bbl do pretty much same job? Just want to make sure before i buy the parts

 

X2 on the high octane fuel. Adding a lead substitute occasionally surely won't hurt anything at all and can only prolong the life of the valves and guides however many people believe that the modern fuel formulas today have lubricants that do the same job as the lead additives did. It is sort of a "toilet paper off the front or the back of the roll" kind of disagreement. If you feel better using the lead additive then do so, it won't hurt. I may have missed welcoming you before so here it is, Welcome to CO.

 

I suggest you find a 4 barrel intake and carburetor for your engine. The 4 barrel will give you better performance IMHO. Quadrajets are the way to go. You just have to decide how much you want to spend. You can get a new Edelbrock carb and intake from Summit for about $500. You could find an old Quadrajet and factory intake for around $100 if you are lucky.

 

Welocme aboard, Its a convert. whats not to like. Put the top down and enjoy the summer.

X2 on checking the timing, you might be supprised at the difference it could make. If you what to stay original you can find stock four barrel manifolds here and on e-bay, craigs list, etc. Just give your location and someone will contact you. Carburators are a personal choice thing you will find several different opinions on which is best. Good luck

 

You can get a Edelbrock performer intake for street use and it will work with the quadrajet very nicely. It also fits the HEI (electronic) distributor which you may eventually want to switch to from the points system your car came with.

If you have duals now, custom or not, a 4BBL is the way to go. Just get a pre-1975 qjet, rebuild it yourself or get it done. Or go high dollar and get a new one from Edelbrock, SMI (Sean Murphy Induction), or others.

 

how much is the distributor go for? just for better spark? and also quadrajet would i need special carb for it

 

In 1968-69, I drove almost every new 88 that came through the dealership. Without opening the hood, it was impossible to tell whether they had a two-barrel 455 or the Highway Patrol engine when driving in town. Above 60 or so, you could really tell the difference, but in town, the two-barrel was really responsive!
Check your timing chain slack and if that's okay, do a good tune-up on what you have before changing everything.
DW

 

Hey great hear all the advice. i also have 67 delta 88 vert. And I had many of the same questions. i agree check the timing and do a good tune up the difference is incredible