68 Inline Intake and hedder ?

[Helidoc]

Hi, I have a 68 2WD 6cyl. I have the original I6 and have mated it to a 700R4 I was going to swap to a V8 but decided to do something different. I am installing a Clifford 4bbl intake, split hedders and Edlb Carb. Does anyone have any pics of the install in their trucks? Has someone here done this before? Any problems I should know about? Oh ya does anyone know where I might find a inexpensive Electronic ign. for a 250 I6. Thanks Stu

[shelby987]

Here are two links to posts I made during my install, one deals with an interference issue you will run into with the trans cross member when trying to hook up your headers to an exhaust, the other deals with issues I had with the carb/intake.

http://www.67-72chevytrucks.com/vboa...d.php?t=200407
http://www.67-72chevytrucks.com/vboa...d.php?t=198709

Known problems
-Make sure the intake and header surfaces are square and true (prone to leaks due to out of flat issues.....carb problems due to loss of vaccum)
-to run a 4bbl carb you will need to make up a cable throttle linkage (I can take more detailed pics if you want to mirror mine (very backyard mechanic at the moment.....all home depot supplies).
-if you run PB you will likely have interference issues with a 4bbl carb (I have a 3/4t booster, a 1/2t might give more wiggle room, I only had 1/8-1/4")
-you will likely need a smaller diameter air cleaner regardless to clear the booster, I bought mine at murray's discount auto for $10.
-If you have a manual transmission, you can work around your Z-bar for your clutch, but you will have to have the headers in place, then re-install the bracket and z-bar (bit tricky, as you will read below, a helper to hold stuff up top and down below at times will really help)
Getting the whole thing put together is a bit more difficult than you might think, a helper will make a WORLD of difference, you have to essentially put both on at the same time, since they use the same bolts to mount up to the head, I ended up using two milk crates to hold the headers in place, but if you bump the headers with the intake, you need to start all over again (only have 1 dowel pin for each header). If you have the clearance to the booster, it would likely be easier to install the carb after the intake is mounted, because of my lack of clearance, I had to install as a set, otherwise the carb would be cocked to the side, and wouldn't slide onto the intake studs.
Also, I replaced my original hardware with new bolts and grade 8 washers, you can do this for all but 2 of the pressure washers, as they compensate for a thickness variation.
I would recommend torqueing it all down, go get yourself a bear, then go torque them again, I used a line fitting wrench, as the additional contact on all 6 corners let me put a little more torque on the bolts without rounding them out.
Lastly, make sure you fire it up at least once with open headers....might spur you to put some cut-outs on the exhaust!

[shelby987]

just read you have a 700r4, so disregard.
with regard to an elec. ignition, hit up ebay, "chevy 250 hei" should not cost more than $25-$30, or I have seen them on the parts board.

depending on where in ohio you are, I might be able to help you out.

[Brad]

Could you show pics of your cable throttle linkage? I'm getting ready to do this myself.

[shelby987]

This is the best I have available right now, its just two tie in straps from home depot. The one that runs the perpendicular to the fire way has holes drilled as necessary to accommodate bolts on the base of the carb, and a cutout to accommodate the bolt I did not use for my PB booster.

The piece that runs parallel with the first wall is piece that was for a 90 degree bend, I drilled a couple of hols in it to tie it to the one on the carb and to bolt it to the intake (my intake happened to have a bolt hole about 4" from the base of the carb.

The rest is just a 2.5" bolt, 3 nuts, and a couple of lock washers. I put the cable linkage to below the head of the bolt and snugged it between that and another bolts. Then I used the other two bolts and lock washers to set my height of the bolt (make sure you have enough travel to the linkage to run the carb to full open).

Lastly to attach the cable to the pedal, I purchase a bearing with a hole for threading the cable through, once you thread the cable, you lock it in place with a small set screw. I am going to wrap the wire around this, and attach it to itself just to ensure if the set screw falls out, I still have a connection. I will get better pics. tonight if you need them.

[shelby987]

oh, P.S. I haven't been able to drive the truck yet, due to other issues, but it sounds and feels AWESOME! (well worth the headaches if you are an I6 fan)

[Brad]

Thanks for the pic and description. I'll have to come back and read it later- I'd love to see some more close ups of that as it's still a little confusing.

[ThatOneBlue67]

Haha, I'm thinking about doing all that except not an entire 4bbl. Too much for the 230 I think. I'm gonna shoot for an intake that supports (2) 1bbl carbs. I heard synchronizing could betricky, but that has to look awesome. Multiple carbs on an inline 6?

[chevroletman19712001]

you guys are lucky. to modify the 250 in my 79 i have to get a whole new head. (mine has intigral head and intake) I might do that somedays tho. As far as the open headers thing, its gotta be louder than regular exhaust manifolds. i just got the pipe going to where the muffler hooks up, but without the muffler. sounds aaight' but not loud

['68OrangeSunshine]

Pertronics makes an electronic ignition that will fit into your old points-type Delco distributor. Ignitor II, I think. I'm still using points, but have the unit for later.
I have a 292 L6 with Clifford dual headers, Offy intake, Edelbrock 500 CFM AFB. I modified a throttle cable from a '72 Chevy combined with a Lokar cable to upgrade my '68 accelerator system, but it wasn't easy.

[Helidoc]

Hey Guys Thanks a bunch for help, I am getting my son to help me out in the morning. I thought they would be a PITA with the seperate pieces but we'll get it. lol . Oh and be for sure I will crank it up with open hedders. Will a SBC water neck fit the little inliner? I do have an assortment throttle cables and the 700R4 cable to sort out. I think it will make a good combo along with the elect. ign. I am trying to get the engine compartment detailed before I complete the build up. Next is the Frt disk brake conversion.

['68OrangeSunshine]

A small block thermostat housing would fit mechanically, but would face the wrong direction to meet the radiator hose. I know I broke the OEM cast-aluminum t-stat housing some years ago and was surprized it was hard to find. I was broken down in a bad part of town. The counter guy at Pep Boys dug around the back and came up with a beefy cast iron housing he said was for a T*y*ta, but it fit OK and the hose end was at the right angle. No p/n, but it had a 1/2" NPT bore in the top for a temp sender -- which I plugged. I hurriedly painted it Chevy Engine Orange -- and it's still on there. One engine later.

[69chevytruck]

Keep us posted. I learned about the headers and intake while attempting to install them and before reading any of the threads. One thing I did was pull the dowels on the end of the head/headers and used SS bolts to hold it all on.

I am running an offy 3x1, with rochester M/MV. It ran great until I pressured washed the engine. Now I get to dig through everything.

'68 orange sunshine, did you have problems with the headers holding up the front of your intake?

['68OrangeSunshine]

Yes -- is the simple answer. I think some clearance had to be ground out of the header flanges to clear the intake. Both components have been on the pickup since 1978. That 292 ran from '77 to '02. I rebuilt the original block and it was on the road by Jan '05. I don't remember a lot of the details -- sorry. I know after crushing the #5 downtube before the collector [while boony-hopping] I had to have a custom shop patch it up. At the same time they resurfaced the headers with a 3/8" flange and devised an angled crossover tube for the exhaust and installed mufflers and dual exhaust pipes.
When I got the latest engine in, I had manifold leak problems and went for overkill with a Clifford header gasket coated both sides with Permatex copper-spray-a-gasket and when that dried hi-temp silicone on the gasket/ header side. I also junked my 25 year old fasteners and went to studs in key positions. 4, 3, 1, and 8, I think. Stainless bolts in other positions. I even used a hardened steel rocker bearing in the #2 spot -- it was perfect.
The pros like Leo Santucci and Larry Page use all studs on the manifold mounts. Studs help hanging the intake and headers so you can get the threads started.