Me again. I've just recently discovered that the "new" carb on my '84 Z28 was actually an Ebay Special and is extremely worn out (loads of play in the throttle blade linkage rods, rust, etc) so I'm probably gonna get a new carb for it reasonably soon. It's currently got the 600cfm Edelbrock with "economy" jets for the primaries, which is a bit of a joke as the car gets about 13mpg on a good day. I'm planning on a few upgrades - was going to do a full engine swap but it's absolutely spotless inside and has fantastic oil pressure (40psi hot idle). The only real issue is the valve stem seals are gone, but I'm planning a head swap anyway. I'm looking at making maybe 250-300 hp, just enough to make the car fun but still streetable. If I buy a 650cfm as the replacement, would that be enough for that horsepower range on a 305, or should I go for 700?

The 700R4 question is pretty simple; I know they have something of a bad reputation for failing under not-very-high horsepower and torque loads, would the stock 700R4 be able to handle that much power or is 190 already pushing it? I'm planning on a new, overkill trans at some point - I just want to know if I'll have to limit myself to avoid rapid unscheduled disassembly in the meantime.

Make sure to get the correct 700R4 linkage arm for what ever carb you choose. It has the right geometry for the TV cable, which has to be adjusted correctly. If not, you will burn up the transmission in no time.

I run a 600 cfm, 1406 Edelbrock on my mild 350.

Here is a link for you: https://www.thirdgen.org/forums/carb...-tv-cable.html

Thanks for the help, guys - honestly surprised a 600cfm can support anything stronger than a stock 350, but I only have extensive experience with single-barrels. Anyone know how much the stock 10-bolt rear end with stock gearing can take? I'm looking at a custom fab Ford 9" if I have to, but I'd rather not spend the extra $2500 if it isn't needed.

ONLY $2500 ???...

Unlikely.

The 10 bolt strength depends a LOT on the year and what diff is in it, etc.

GD

Probably more than that by the end, this is what I was looking at. https://www.moserengineering.com/9-F...d-Package.item

That's a HOUSING. Not the differential itself. The 9" uses a third member design. And by the time you do calipers with parking brakes, powder coat it, etc you are looking at $3,000 for the housing BEFORE shipping and then likely another $1350 for the third member plus shipping for that..... Easily close to $5,000 by the time you are done. Oh and it's not likely that you will be able to fit your stock wheels. So wheels and tires as well...... for a 305.... LOL. Upgrade the 10 bolt or get a 9 bolt to upgrade. I have 400 HP in front of my upgraded 9 bolt with a Torsen. I need more tire but even still I wouldn't be afraid of breaking it.

GD

It would fit the stock wheels.
I've seen them from Quick Performance for $3500...

Oh no. Just realized that's only the price for the housing. Why the hell is it so expensive?

Edit: and also I haven't been getting notifications of new posts, that's neat.

Supply and demand mostly. Not that many people putting these into third gens.....the 9" is popular but it's old, and Ford doesn't use it anymore. And there are more efficient designs available now like the Ford 8.8 or the GM 12 or 14 bolt (which is a monster).

GD

I don't know why Ford went to a C-clip axle retainer design for the 8.8". That's like going backwards in technological progress...

Anyone know of a good primary jet size for a 600cfm? Mine's leaning out at mid-throttle, but it's fine once the secondaries kick in.

Why not a Quick Performance housing? Way less bread than the Moser. They seem really proud of that.

That said the stock axles "depend." Some people break em with stock power and others beat the snot out of them and run single digits with tire. Depends on a lot of things (weight, power, tire) and maybe a bit of luck. From what I understand higher numerical gears make this problem worse as well. Then again I knew a guy with an S10 that'd draw lines down the axle shafts so he could replace them if he saw them starting to twist.

Have you tried different metering rods yet?

I haven't tried anything but adjusting the mix screws on the front yet.

Read this: https://www.fordmuscle.com/archives/...etor/index.php
Attached is the Edelbrock manual.