first engine mod's

[Cowman85]

hey i have a stock 86 350 c20, i am looking for an extra kick but i want the same fuel mileage or better (who doesnt i know), the only go i need is in city, light to light etc.
th400 3spd is what i have in there but i dont know the gears

i know i need a cam but what else would be best and fairly cheap to change (still going to school), my baby has 153km on it right now and the guy said the heads were done a couple of years back. looking to spend up to 700 ca.

the exhaust will be done before this but for that setup what type of header would be best suited?

 

[VileZambonie]

Find out what you have for gears.

[eventhorizon66]

Are you saying that you never or rarely take it on the highway?  In that case, you can run some pretty low gears and actually improve city mileage, along with acceleration potential.  But take it on the highway and kiss those mpgs goodbye.

[Cowman85]

well i hit the ring road the other week and even doing 105km/hr it still burnt a bunch of gas, enough that i will NOT be taking it on the road much, i would love to change to a 700r4 or put in OD but i'm on a student budget and this is my first real project.

i will be checking the RPO listing in the glove box but it will take a few days, is there another way to check the gearing?

if i could improve everything overall then i might just take her on some long hauls (God knows she would come in handy)!

[Just-speed]

well i hit the ring road the other week and even doing 105km/hr it still burnt a bunch of gas, enough that i will NOT be taking it on the road much, i would love to change to a 700r4 or put in OD but i'm on a student budget and this is my first real project.

i will be checking the RPO listing in the glove box but it will take a few days, is there another way to check the gearing?

if i could improve everything overall then i might just take her on some long hauls (God knows she would come in handy)!

   You can get a 700r4 for less than $1000. Can you install yourself?   

[werewolfx13]

Whats it getting for mpg? I drive mine on the highway whenever I need to, and I get 8 city/13-14 highway at 60 mph..I personally wouldn't make much in the way of changes based increasing mileage, unless you want to drop a big stack of bills on it, you're not likely to hit 20+ mpg, and the difference between 14 and 17 would take a long while to make up the costs..But, a basic tune up (cap, rotor, plugs, wires, trace and eliminate any vacuum leaks, check timing and adjust if needed), carb rebuild, a set of tri-y style headers, a good aluminum aftermarket dual plane intake manifold are all things you can do to improve both performance and economy..As for your exhaust, I suggest you pick up one of the stainless x pipe kits from this site's store. Modify it if you need cats, the muffler prices are also fair so I'd snatch a pair of whichever muffler options you want with the kit.

[Cowman85]

i'm sure there are some sites out there for a 400 to 700 switch, would it bolt right up or do adjustments have to be made?

[Cowman85]

we will see what the difference in fuel mileage is now that the fuel problem is fixed, i should be picking her up this weekend.
I've done a tune up though:

castrol full synthetic
extra guard oil filter
slick 50 treatment
new wires
new plugs
flushed coolant
new battery + dual
air filter
pcv
fuel filter

i still have to do the cap, rotor and check the timing, fixed all my vacuum leaks and spray cleaned the carb. When i do spend some money it will be on the carb and the headers/exhaust to start.

The things i would need to determine are the combination and the model of internal engine parts i should replace: cam, heads etc.

Also debating the purchase of a $300 500cfm carb, something small and efficient and CLEAN, it should increase gas mileage right? that would also give me a chance to rebuild this q-jet.

[enaberif]

If you want to spend money on a carb look into a Edelbrock 1406 with electric choke they seem to be pretty highly recommended next to the qjet.

In regards to the gears you have.. Go out on the highway get upto say 100km/h which is about 65mph and make a record of your rpm.

Then you can use a calculator to find out or close to what you have for gears in the back with a calculator.

[Cowman85]

That carb seems like it would be a good fit, i'll have to call and get a price here, thanks for the recommendation!

I dont have a tach unfortunately so i will have to estimate the rpm.

[werewolfx13]

IMO, stay away from fram filters like they're a plague, since really, they are.
Wix filters (napa gold) are a very good, cheap filter, and the only filter I run in any vehicle. My future father-in-law is the same way.

The 1406 is a good carb for bolt on and go, I'm partial to manual chokes instead of electric, but to each their own.

[TexasRed]

I'd rebuild the Qjet. .. . the 1406 ain't a bad carb. .. .should work well, just won't give the mileage a properly setup qjet will.

[Cowman85]

never heard that fram was bad but thanks for the tip,

took a look at my RPO codes in the glove box and there were a couple i couldnt find any info on or contradicting data:
23D
ywx
xwy
n41 - power steering right?
MX1 - says "merchandised trans, auto provisions" guy told me it was a 400 but some rpo pages say 350?

does anyone also know the significance of the V class chevys? (v10,v20,v30,1987)

My Gear ratio is 3.42 (GU6)

[Captkaos]

MX1 is the standard transmission for that particular year.
Example 1987 C10 MX1 = TH350-C

V series is equivalent to the 73-86 K series, they just changed it because the 1988 new bodystyle took on the C/K designation.

[Cowman85]

good to know, thanks!

its a th400, stock.