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1978 Blazer/Jimmy projects

Diesel4me, I did not know it was that easy. I'll definitely crawl under there this weekend when i get home and check it out. Thanks again for the input so far.

Another question: Are all quadrajets pretty much the same. I have one that ran okay on my a 79' K5 i used to own that had a 350SBC. When i ran the numbers though it came up as being off a 1984 305SBC.. Would it be worth rebuilding and putting on my 400 SBC? (Assuming i'm sticking with a quadrajet setup)
 
If its not one of those electronic feedback Q-jets its worth keeping--it'll have wires going into the top of the carb if its electronic...if not I'd look for an older one,built before 1980 when they started putting computer controlled ones on some trucks...you can run the electronic ones unplugged but they run way rich and your better off with the older style ones..
 
Mostly 76 or later non computer carbs, can be electric choke or easily converted to electric ckoke from hot air. Older carbs and some post 74 truck carbs are divorced choke using manifold heat and can't be converted to electric choke, you need an external kit.
76 and later have more adjustability for diff apps.
 
Thanks guys, I'm pretty sure it is not an electric carb. I'll have to take a closer look at it an post pics when I get home this weekend. It's not a divorced choke, and currently has a new manual choke that was recently installed. If I remeber correctly the number was something like 170284322 when I bought the rebuild kit. I'm going to rebuild it regardless just for fun and to get some hands on experience since I've never done it before. Whether or not it will have the correct CFM to work with my 400SBC is my concern... and I hope it isn't a pain in the A$$ electric (pretty sure not).

Another question on the subject would be: Are there any good manuals worth getting ahold of to walk me through doing a first time full carb rebuild? So far I have the instructions from the carb kit and a 1979 GM shop manual, but the more descriptive info the better.
 
There are specific books with instructions on how to rebuild and tweak Q-Jets,one if I remember right is written by Doug Rowe and deals with multiple Rochester carbs...

A Q-jet is able to work on many different engines without needing to be re-jetted in many cases because its air valve secondary valve limits how much fuel gets delivered to the secondary barrels,it will open up as much as the engine can pull,thats it...that is why you see some Q-jets as large as 800 cfm's used on smaller V8's like 305's...they even used the lower cfm rated ones on old Pontiac OHC straight sixes..

Going by the carb number you listed,I think its a 1978 carb..the 5th digit I'm pretty sure indicates what the year it was made in..
 
Cliffs quadrajet is the latest, he has a website with a forum and parts/ kits good for today's fuels.
Doug roe is good but I prefer cliffs book plus you can call cliff on the phone.

Cliffshiperformance. Com
 
According to Carbs Unlimited specs on Google,its used on 1981 - 1986 GM trucks,800 CFM...plenty of flow for your 400 SB!..
 
As long as your dealing with relatively stock motors you will be fine, no big cams.
Get a kit from cliff which includes float and acc pump, get his book.
Make a note of what your jets rods and 2ndary hanger are for future reference.
Post your application and carb # on his forum and someone will chime up, cliff will eventually answer if he has something to add. Or call his office.

Don't but a cheap kit.
 
Thanks for the carb info diesel4me and blazer74. I'll be returning my autozone kit getting ahold of Cliff for sure about one of his carb kits as well as the repair manual.
 
I made a little progress this weekend. Out with the old tank and in with the new. I wiped it down with acetone and then put 8 layers of POR15 on the exterior. All hose was replaced with high pressure fuel injection rated hose as recommended earlier. I also pressure washed the skid plate, but did not have time to refinish it with POR15 or install it.

tank.jpg

tank2.jpg

tank3.jpg
 
Yeah, I guess I'll just bite the bullet if anything happens between now and the end of my 3 year warranty. If it were a lifetime warranty I 'd feel I made a bad choice in "altering" the tank, but I think it was a sound long term decision.

...And as far as the carb goes, I have an SR kit and book on the way from cliffshiperformance
 
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Yeah, I called spectra and asked them about it, I'm going to install my new tank soon and leave it bare for a while.
They wouldn't even recommend a paint for the tank.
 
Good choice on the carb kit and book, his kits come with more than an off the shelf kit. And free tech advice.
Did you get a chance to chat with cliff? He stays quite busy.
Better painted anyways on the tank, 8 coats Por15, you've got more patience than I do.
 
Being galvanized,I think maybe they are afraid some paints like an etching primer may actually do harm instead of good?...

I used "cold galvanizing compound" in spray cans (made by C-R-C ) to coat the stock tank in my '81 G10 van and its still looking very good--on the outside at least..but having been empty the past 10 years sitting in my driveway off the road,I'm sure the inside is probably ----(censored)!..:doah:...
 
I used a scotch brite pad and acetone to prep the tank. This removed the thin coating of shipping grease from the exterior as well as scuffed up the galvanized finish a bit to help the paint stick. The paint was the Por15 chassis and frame blend out of an aerosol can. Had I done it again I'd have spent the extra $20 on an additional can of the Por15 rubberized spray coating instead of using rubber cement and anti-squeak (tar paper) strips on the contact points between the tank, tank straps, and the body crossmembers. I don't like the idea of something that can absorb moisture contacting my metal tank.

Spectra was the brand I ended up getting over the Dorman, and I opted for the 31 gallon instead of the 25. Kinda like having an extra 1 & 5 gallon jerry can without having to mout extra cans.
 
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