Keeping my I6 250...what to do?

[crazyjeenyus]

Here's a few things that I'm surprised no one has mentioned yet:

Look at installing a lump port kit in your head, those inline six heads were not designed well, and lump porting will vastly improve flow. Heck, even if you cut out the bolt bosses on the intake runners your flow numbers will increase substantially.
This will also allow you to more properly utilize a 4-barrel intake & carb and headers.

Another inexpensive upgrade that a lot of guys do is swap out your stock slugs with a set of aftermarket 307 flat top Pistons. They'll fit your block perfectly, and greatly decrease your rotating mass.

Now you can choose a cam, something in the 260-280 range would work well with the other upgrades. Always install new lifters with a new cam, and a set of roller-tipped rockers would be perfect.

This is about all you would want to do to a little 6 banger aside from adding a turbo or supercharger which I'm not really a fan of.

I'm actually in the process of building up a 292 for one of my projects ('50 Chevy Deluxe).

I've got some +.040 Silv-o-lite flat tops
And a comp 280h cam
Plan is to acquire a lump ported head and go from there.

Good luck with your 6. It's always nice to see one that's been beefed up, and they have a great sound.

[HO455]

I have a different opinion. I have run the base model Pertonics units for decades now and not had a failure. But if I ever did, the points and the rest of the pieces are bagged up in the glove box ready to get me on the road again. That isn't an option for an HEI, unless your willing to carry a spare distributor. Tomatoe or Tomato.
And as far as what else to do with your 250. Drive the wheels off it man!


P.S. (Pertronics got bought out and the company's new products are not up the the engineering standards of the old owners. The old line of products are still as good as they used to be. We wont install any units but the basic ones. Lesson learned the usual way.)

[bill3rail]

I run Petronics ignition, never changing points again (Or filing them on the side of the road to get home) is nice!

['68OrangeSunshine]

I had a Pertronix Ignitor II on my 292. Worked good for about 7 years, then it would mysteriously cut out at 65 MPH, 3000 RPM. Engine would ''black-out'' deadrolling at freeway speeds until I could kick in the clutch, turn ignition Off then On, and pop the clutch at 55. I went back to points for a year. One theory was Desert Heat, another theory was it was getting spiked by high voltages from the EVR.
I emailed Pertronix customer service about it. They said send in the Ignitor II and they'd check it out. So I sent it in and never heard from them again.
Now I have a remote coil HEI and I'm happy with it.

[stevenfromtexas]

"remote coil"??

HEI that has the coil still mounted to the block and not inside the cap?

i'm interested...

['68OrangeSunshine]

Originally Posted by stevenfromtexas

"remote coil"??

HEI that has the coil still mounted to the block and not inside the cap?

i'm interested...

Yeah, on the '75-'77 4.8 L6s [292s] there was cap interference with the big cap hitting the passenger side of the engine. Some fancy finned-aluminum custom side lifter covers had a dish milled where this occured, but I had clearance issues with stock covers.
Mounting the coil on the head [basically where the points coil went] lowers the action. It's a different cap too.
I can't find the pic. It's still on the SD card and not in Pictures. Working on it.
Got 'em.
Low Boy cap and custom coil bracket.

['68OrangeSunshine]

I got a couple of caps from ebay, They were $5 each. The pigtail I got from RockAuto. Coil from Merle's Auto Parts in Tucson. Order parts for a 1976 Chevy C/10 w/4.8 Liter L6 [292].
Had to fab my own bracket to hold the coil.
The OEM bracket straddled between the front bolt of the rear lifter side cover and the rear bolt of the front cover. There was a 1/4''-20 stud on top of these bolts. Coil mounted on a U-shaped bracket between the lifter covers. Hard to find now.
I mounted my coil upside down for better reach to the distributor pigtail. Looks cleaner, and plugwire terminal doesn't stick up.
Coil is attached by 2 bolts on ''front'' of coil. Adequately secure and allows reach behind to #3 sparkplug.

[stevenfromtexas]

WOW!! thank you very much!!! i will for sure keep this in mind. i want to ride this little guy for a while then revisit this thread for the info about the cam upgrade and deffinatly the HEI

thank you again for the pictures and info!!!

[RichardJ]

This is how the factory mounted the coil. The two center most bolts on the side covers have threaded studs above the hex.

[stevenfromtexas]

thank you!!

[RichardJ]

Found a better picture of the coil on my computer.

Crazyjeenyus, is giving you good info about the engine, but in my opinion, without the other changes to the truck, more power won't make it a more enjoyable truck.
My 292 has the LPG 9:1 pistons, 1.94 In valves, roller rockers, cam, Carter AVS, Clifford, Hedman, but I was still in the slow lane with the engine screaming its heart out. It wasn't until I changed the rear gears was any of that worth while and it could run in the fast lane with anyone. I know the stock engine configuration would have been equally happy with better gearing.

Before the power steering, I always felt like I was wrestling a grizzly in the cab when I was trying to park it. Power steering allows you to get rid of the giant steering wheel they put in there to give you leverage to wrestle the grizzly.

AC speaks for itself. There's nothing fun abut sweating in a truck cab no matter how much power it has.

[stevenfromtexas]

hahaha wrestling the grizzly....i agree
A/C as well. i told the wife how much fun it will be to meet and hang out with "old car guys" and cruise. she said, "will there be A/C"? hahaha
pretty sure that will be the first "upgrade"

what rear end gear ratio would be the best? highway gears was in the plans down the road

i haven't checked mine. its all stock '67 swb with 250 engine

[In The Ten Ring]

Added this to "Truck Work" favorites folder! I have the 250 also and it could use some upgrades later on.

['68OrangeSunshine]

Originally Posted by RichardJ

Found a better picture of the coil on my computer.

Crazyjeenyus, is giving you good info about the engine, but in my opinion, without the other changes to the truck, more power won't make it a more enjoyable truck.
My 292 has the LPG 9:1 pistons, 1.94 In valves, roller rockers, cam, Carter AVS, Clifford, Hedman, but I was still in the slow lane with the engine screaming its heart out. It wasn't until I changed the rear gears was any of that worth while and it could run in the fast lane with anyone. I know the stock engine configuration would have been equally happy with better gearing.

Before the power steering, I always felt like I was wrestling a grizzly in the cab when I was trying to park it. Power steering allows you to get rid of the giant steering wheel they put in there to give you leverage to wrestle the grizzly.

AC speaks for itself. There's nothing fun abut sweating in a truck cab no matter how much power it has.

Richard: What are the two vertical 3/8-18 bolt holes between Cyls 3 and 2 used for? Hangover aircleaner support? I've always used them for coil mounting. When I had points, I hung a big square Mallory Voltmaster coils on those 2 holes. They were vacant on my engine.

[RichardJ]

>> two vertical 3/8-18 bolt holes between Cyls 3 and 2 used for? Hangover aircleaner support?<<

Yes, but also for the AC compressor bracket. That last coil picture looks like it was taken before the AC installation. I use the bottom hole there and the two holes at the front next to the #1 plug.

[G8rN@te61]

Originally Posted by RichardJ

Found a better picture of the coil on my computer.

Crazyjeenyus, is giving you good info about the engine, but in my opinion, without the other changes to the truck, more power won't make it a more enjoyable truck.
My 292 has the LPG 9:1 pistons, 1.94 In valves, roller rockers, cam, Carter AVS, Clifford, Hedman, but I was still in the slow lane with the engine screaming its heart out. It wasn't until I changed the rear gears was any of that worth while and it could run in the fast lane with anyone. I know the stock engine configuration would have been equally happy with better gearing.

Before the power steering, I always felt like I was wrestling a grizzly in the cab when I was trying to park it. Power steering allows you to get rid of the giant steering wheel they put in there to give you leverage to wrestle the grizzly.

AC speaks for itself. There's nothing fun abut sweating in a truck cab no matter how much power it has.

Liking the offset air cleaner. I have the top piece but not the bottom piece. Do you happen to know what I should look for?

[In The Ten Ring]

Originally Posted by dash13

Here are some pictures of it now.

Whoa! That rubber fuel line and filter going to a metal hardline is a neat idea. That way you can get a good seal on the flared ends without too much trouble!

Is there any danger of a fire with that set up?