Inliners International Forums General Discussion Engines 250 Integral Head

Picked up a real nice 1978 Nova coupe with a 250 P/S, P/B and A/C but want to eliminate all the smog item so am thinking of replacing the head with an earlier style. If I remember correctly these heads will bolt right on. Will use an earlier intake and headers and also reading the latest 12PN saw the article on the Triple Accessory Drive System from E.C.I. Couldn't find the exact system on their website, only the V8 items. Curious as to the price as this would work better on my application. I know the P/S and A/C brackets are different between the integral and non-integral head. Just want a nice daily driver.
Tks..

Yes GMDad the other heas will bolt up. But you may run into a issue or two with mounting what came on the other.Some bracket holes may not match up.

FOR a d/d i'd leave it stock. also "if" you do chage stuff around "keep" the original parts so you can put it back together all original if need be.


jmo
bob

That is why I am thinking of the mount kit from E.C.I. Stock is OK but I have never seen so many vacuum lines under one hood at one time in my life and it has a fairly large catalytic converter right at the exhaust manifold along with the smog pump, etc.

you,ll have to deal with all those issues more drastically if you go to old style head. also the 2 piece manifolds are more prone to leaking, thats why they changed the design. for a d/d you can get what your looking for with the head you have and not deal with all the hassle IMO
Bob

GMdad Just a FYI - I used a 78 nova front clip in my '51 gmc. The 4200 is an easy install once the oil pan is mod'ed I reused the OEM frame mounts and made brackets with 3/16 plate and 2x3 box tubing. The trans cross-member can be reused.

Start to end 2 days of fab for the mounts would have a 4200 bolted in. $99 to Limequat to re-jig the PCM. The 78 has a common fuel tank fuel pickup neck upto early 90's fuel tanks so you could reuse a j/y pickup/in tank pump. The rest is plumbing.

Start to end 4 weekends and it would be running. A good running 4200 can be had for $500. All in I bet it could be done for $900.

Keep the OEM motor if you ever wanted to restore it. Bonus is no chassis mod's.

Do you think there would be enough hood clearance with the new style motor?

Yes I believe so. While the 4200 is wider, its not as tall as a 292. Once the front sump is moved the motor fits nicely on the nova cross member.

Even an early 4200 with a good exhaust will make 280ish HP.

Last weekend I helped a buddy extract a 2005 4200 at the local u pull it yard - complete with harness, PCM and all the small bits to make it work $300.

efi,
I know this is off topic, but do you have any more info on the subframe install on your '51? I thought the later Novas were too wide to use on AD trucks. I have two of them sitting out back and I would like to put at least one in an AD if it will work. Did you narrow it?

Stock width...

51 front shot

I'm with bcowanwheels - keep the old stuff around - and get lots of photos on how it is all plumbed.

In Ohio after a vehicle is 25 years old there is no-longer a bi-annual inspection/smog-test imposed by the State. And transfers within the state do not require inspection - so an altered '78 could be easily sold within the state. But bring any vehicle into Ohio from out of state requires visual inspection - regardless of age - and all factory smog equipment would need to present.

In the US it is technically illegal to operate a vehicle without all of the manufacturer installed emission controls. Prior to '72 motorists could freely modify vehicles. Between '72 and '74 is a somewhat gray area. After '75 (in Ohio at least) altering anything between the manifolds and the cat is considered 'tampering' and is illegal. Piss off a cop and they could add equipment violations on top of your other ticket . . .

Not sure if it is the same with the 'Provincials' in Canada . . .

regards,
stock49

I used to live not far from GM Dad..

The last time I checked in Ontario, vehicles over 19 years are exempt from emissions checks. And there was a provision for hot rods to allow engine swaps to be done and be exempt.

With gas running 30% higher in Canada than the US, it makes good sense to swap in a motor that will reduce your fuel consumption. Ontario gas is running $1.10/liter (about $4.17/US Gallon). A 30 to 40% drop in fuel consumption will pay for its self,how long depends on the distance driven. After that its money in the bank.

I'd keep the original parts to restore it too.

You lived in Ontario? Where abouts? The emission test deal is still 19 years and newer. Just require a mechanical fitness certificate on any car now and if it is over 20 years old, has to be appraised for sales tax purpose before you can put the ownership in your name.
A bit of a catch 22 situation. If you get a lowball appraisal for sales tax you have that same appraisal for insurance purposes. Even a written receipt from the seller is no good. Unless it is a used car dealer and the sales tax is paid when you buy it. Not sure how the mileage will be with all of the Calif. pollution equipment on it. Will more than likely drive it for a bit first and then decide.

this 4200 engine, will standard early gm bellhsgs bolt up ?

Nope, you need an adaptor.
EFI-DIY knows the cost.

MBHD

Mississauga close to square 1.

The OEM trans used with the 4200 is a 4L60E and the 4200 pcm is set up to run it, so it kind of makes sense if you want to run an auto to install the engine and 4l60E trans at the same time.

If you want to run a manual trans then the colorado MT is a good start. You will need a flywheel from Jerry W.

will ac bracket from a later model integral head fit a 71 250?

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I extended the adapter to add material to allow the adapter to also serve as a mid-engine plate.

Still seems to me that swapping a head and intake is a lot simplier and cheaper that doing an engine swap.

Simpler -- less thinking required for a mod than a swap - so agreed, cheaper - depends Same power output - no

Starting assumptions:

target has an open rear end
a rolled trailblazer/envoy was obtained for a donor
the 4L60E trans was also swapped at the same time

Work involved:

modify/buy a rear sump oil pan
make motor mounts
adapt the trans mount
install the engine/trans as one
make the drive shaft fit as needed
install an EFI feed & return line and efi pump
install the DBW gas pedal
send the PCM to Limequat for mod's
wire the engine according to Lime's wiring instructions
install the shifter out of the donor (its cable operated)
plumb the rad/heater hoses & trans cooler line
mount the donor air cleaner or replace with aftermarket