Looking to put 350 HO in my 1985 F-body with L69, 5 speed
The car is my daily driver
Want to retain stock electronics and emissions
Year One Catalog says that this engine is designed to replace the L69 with the TH700-R4 trans.
Any problems with my application?

 

Do you need to be smog legal? Here is what the GM Performance Parts catalog says about the HO350 package, "Chevrolet engineers have developed an emission-legal conversion kit to install a High Output 5.7 liter (350 ci) small-block V8 in a 1982-87 Camaro originally equipped with an LG4 or L69... and a 700R4 automatic transmission...."

There is an instruction manual available (or at least it used to be) p/n 24502463. That should answer most of your questions.

The conversion package (which came with some nice parts like a dual cat exhaust, etc.) has been discontinued by GM, although some suppliers like SD and gmpartsdirect.com may still have some in stock.

 

The HO 350 Camaro Conversion Kit and the 350 HO are not the same thing.

The HO 350 kit was for automatic cars only, and is, as stated, no longer available.

The 350 HO is a Vortec-headed crate engine for '75-earlier or off-road vehicles (for the purposes of emissions) only. Although it could probably be pulled off, it wouldn't be a straight-forward bolt-in by any stretch of the imagination.

 

Then what's a better choice for a new GM engine for my car?
with 5 speed and electronic Q-jet

 

The 5-speed is a limiting factor. They just won't stand up to torque & abuse. If you are willing to take it easy with it, you can put more power in front of it. But, if you're taking it easy, then what's the point of more power?

On the other hand, many have done it. However, you have to realize that there isn't any "legal" 350 for your car. California has their referee process, so you can probably get it to work there. Otherwise, you're talking about the fact that a 350 looks externally identical to a 305, and as long as you remove all of the 350 stickers, shouldn't be a problem at emissions inspection time..

There isn't a good choice for a new factory long block. The Goodwrench 350 would basically bolt in. Probably wouldn't put out any more power than your L69, though, unless you upgrade/modify it with at least cam, and probably heads.

The ZZ4 is the engine used in the HO 350 kit. You'll need a one-piece rear main seal flywheel, and you'll have to do something about the EGR valve. The valve will bolt to the intake manifold (it's what I'm using, and I passed emissions in November), but won't function unless you plumb exhaust gases up to the intake manifold (the hot air choke boss is a good place to route it). However, if they don't physically check the operation of the EGR valve, the engine will probably pass sniffer with a good cat. I honestly don't know what the inspector will think of the aluminum heads, but if you paint them black like the rest of the engine, they probably won't notice.

Another possibility is to buy a new L98, L31 or ZZ4 shortblock, and put on ported iron World S/R Torquer or Pro Lightning heads. With a computer-compatible cam, the thing would run great and be clean enough for the sniffer.

Another possibility is to just help your L69 with emissions-legal upgrades. Headers, high-flow exhaust all the way back, cam, and ported heads (and possibly a better intake manifold like Action+ or GMPP) would help power and retain emissions-legality. 350 HP gross at the flywheel is certainly respectible, and as long as you resist the temptation for high-RPM clutch dumps, the T5 will live behind it.

 

All I have to pass is the sniffer test

does the ZZ4 have Vortec heads like the 350HO?
if so what intake manifold would work.

If the trans blows up I can deal with that and the rear end then (it's a daily driver, so I don't plan on side stepping the clutch at 4000RPM)

 

the ZZ4 has L98 aluminum heads, the same heads that came on L98 corvettes.

so any '87+ chevy intake manifold will fit, and a '86 and prior will fit with a little modification to the bolt holes.

the 350HO has vortec heads, so you have to buy a vortec specific manifold.

both are good choices.

if you don't have a visual inspection, both will get you through emissions with a good cat.

both make near the same power.

the zz4 has a better bottom end, and has a roller cam.

the 350HO has better flowing heads, and is much cheaper.

 

Actually, they have the '86-earlier intake bolt pattern.

350HO heads are lift-limited. If you want to upgrade the cam sometime in the future, you'll have to pull the heads and have the guides cut and spring pockets cut for better valve springs.

ZZ4 has roller lifter cam, 350HO is flat-tappet.

Both the ZZ4 and 350HO are one-piece rear main seal design, so an '86-up flywheel is required.

 

57kid
did you mean that the pre 86 intake manufold has the same bolt pattern as the ZZ4 and HO 350 heads?

 

Only the ZZ4, not the 350 HO (Vortec).

 

learn something new every day....

 

If I go with the ZZ4 do you think that I will have any jetting problems with the electronic Q-jet

 

The conversion package, to the best of my very fuzzy recollection, came with a different chip and metering rods for the carb. I can't get to my GM Performance Parts Catalog right at the moment. Do you want those part numbers?

 

I'd love to have those part numbers thanks

 

I took this info from the 2003 Performance Parts catalog. Keep in mind also that in each case, the p/n is for a vehicle with an a/t, not a stick. Okey dokey, with that in mind, here is what the catalog says:

Controller, ECM: p/n 88999154
Calibrator, Prom, 1985-87 LG4, 83-86 L69: p/n 24502456
Sensor, Knock: p/n 10456288
Module, Elec. Spark Control: p/n 16128261
Metering Rods, Secondary (AH): p/n 7033812
Cooling Fan Switch (95C): p/n 3053190

Let the money begin to flow!

 

Thanks for the part numbers