67 250 power steering conversion help

[NC67Chev]

So, I've got my hands on a complete set-up to convert my 67 truck with a 250 I6 to power steering. Also, I've got a grip on what needs to be accomplished regarding the mounting of the gear box. Anyway, yesterday afternoon I thought I would go ahead and change the water pump pulley to the new double groove pulley that I got with my set-up. The stock single pulley that I took off of my truck (p/n 3788472CG) measures approximately 7 1/16 inches. The new double groove pulley (p/n 3995646AH) measures approximately 5 3/4 inches. Also, the original single groove pulley is more rounded on the mounting surface (there is a fitted spacer that goes between the pulley and the water pump). The new double groove pulley is larger in diameter and is more flat. When I put the new pulley on, it seems to fit nicely and seems to line up well with the crank pulley. By the way, the donor power steering set-up came off of a '72 Nova. Because of the difference in the pulley diameters, I thought better of it and put the original one back on for now. So, after all of that, here are my questions: 1) Is this sounding familiar to anybody that has previously done this conversion? 2) Does it make any difference if the new pulley is smaller in diameter? Other than the obvious that I will need to get a shorter belt. 3) I'm assuming a smaller pulley will mean that the water pump will be turning a little faster. Is this correct? Is this significant in any way?

These might be very silly questions, but I don't want to make a mess out of my truck.

Thanks everybody!

[passthebuck]

I did the same conversion a few years back & yes, I too had to put the shorter belt on. Didnt seem to have made any difference with the smaller pulley.

[NC67Chev]

Thanks, that makes me feel better. Just out of curiosity, how did you go about mounting your steering gear? Did you add spacers, or did you dimple the frame? Also, did you replace the idler arm? I know the pitman arm obviously will need to be replaced. Anything you're willing to share is greatly appreciated.

Thanks again!

[passthebuck]

I heated the frame up & dimpled it. This is a source of debate on this site. I feel that:

1) You maintain the factory geometry with the dimple (They started dimpling in 68 & didnt use spacers);

2) I'm cheap. I didnt have to go buy anything; and

3) I already had the torch & BFH on hand.

Idler arm doesnt have to be replaced, but it was beat & wouldnt pass safety insp & so I did.

Really, it's an easy install. I had to clean/tap out the theads in the head because they were solid with crap after 40 years. Everything should just bolt up.

If ya have more questions, feel free to ask...

[NC67Chev]

That's exactly what my thoughts were regarding throwing the geometry off by using spacers. Although, since I don't have any heat readily available, I think I'm going to see how things work out by using 1/4" spacers. Do you have a preference regarding the gearbox? I've heard some people suggest that '73 or newer versus '68 - '72 provide a better feel.

[passthebuck]

To get it all set up, I scavenged a box off of a 76 tow truck, but I seem to think that anything will bolt right up until they changed to o-ring fittings in the I think - late 80's?... Just be sure to get the rag joint off of what ever truck you are taking the box from.

Some good reading about steering upgrades here:

http://www.chevelles.com/techref/ftecref29.html

BUT our trucks use a different box than the cars & hence we don’t have the advantage of being able to obtain one from say a Camaro or a Monte SS. I had a high ratio box built for me by AGR & it's a sweet piece. 12.7:1 constant ratio with an aprox .250 torsion bar inside. Takes it from farm truck feel to a modern sport-truck feel. Ya, it was spendy, but worth it. I also put a 1 1/4 sway bar on from the same tow truck & that alone made all the difference by itself.

[NC67Chev]

So, I wanted to update you on where I am regarding the power steering conversion. I thought I had everything I needed to get the pulleys mounted, but I failed to realize that the double water pump pulley that I acquired had 1 1/2 inch spacing versus 1 1/4 inches. Nor did I realize that the water pump assembly had both bolt patterns. This meant that I needed to find a fan blade and spacer with 1 1/2 inch bolt pattern. I was able to obtain the matching fan blade & spacer form the same individual. However, the fan blade is a good bit smaller than what the stock one is on my truck. Below is a picture of my stock fan blade and one of the new fan blade. The diagonal span of the new fan blades is about an inch shorter and the overal height is about 2 inches shorter. My question is, does this make any difference? Obviously, a larger fan blade assembly pulls more air. The power steering set-up I got came off of a '73 Nova. Anyone have any thoughts? Also, does anybody know what the torque specs should be for the power steering pump brackets? Thanks!

[Dark Knight]

You can just line up the center hole in both of the pulleys and drill new holes to match the ones in the old pulley. That's what I did and it works flawlessly.

[passthebuck]

Dark Knight is correct - as long as the centre hub is the same, a little drilling & bob's your uncle.

[NC67Chev]

Thanks for your responses. The pulley isn't the issue. The new pulley I have lines up perfectly. My issue is the fan size. The new fan is a little smaller than the original one that came on my truck. Will the use of a little smaller fan create any issues? Such as overheating? Thanka again!

[passthebuck]

It is very doubtful that it would cause any difference at all as long as your rad is in good shape...

[Dark Knight]

Personally, I would go with the bigger fan (if it fits). If GM put it on there from the factory and it has worked for 40+ years, why change it? (no offense intended ) I guess it really doesn't matter though. You could probably cool one of these little 6 bangers with one of those clip-on fans that some people put on their dashboards.

[NC67Chev]

Thanks to you both. I wasn't on the same page as you two when you were talking about drilling new holes in the double groove pulley. I may very well do that at some point in the future. For now though, I think I'm going to leave the small one on until I get the rest of the power steering upgrade completed.

[NC67Chev]

So, here's what I have so far. As you can see, the twine that I've ran around the crank, water pump and PS pulley interfere's with the nut on the alternator pulley. The solutions I can come up with are 1) Use a shorter belt that just goes around the water pump and PS, which I don't think is correct or 2) Find a double pulley for the alternator. Any thoughts?

[passthebuck]

It may be the angle you have the camera at, but it appears as if the PS pump pulley is not inline with the crank pulley. You may be able to deconflict the belt with the alternator nut by spacing the pump forward. (Or is the alternator too far forward?)

I have heard of guys taking a piece of 3/8" round stock & laying it across the two pulleys to help determine where the misalignment is.

Other possible solutions:

Pull the nut off of the PS pump, shave a bit off of the nut, pull the pulley forward & reinstall nut - this may give you the clearance you need.

Maybe "flip" the PS pulley. It could be dished to the rear & switching that dish to the front could solve your problem...

Keep me posted...

[NC67Chev]

I agree, the angle of the picture does make it look like it's off. When I first mounted it, I did use a framing square to check the alignment. The pulley's do line up very well. I don't think reversing the PS pulley will help, because it has a pretty long taper on the front of it. So much so, that according to my rough measurements, it would throw it out another pulley width. I thinking about stoppng by and chatting with a couple of local alternator shops and see if they have some suggestions.

[passthebuck]

There are a number of ps pump pulleys available. Maybe one with different spacing or one of those dual pulleys may help.

Scroll down to the bottom:
http://www.billetspecialties.com/assets/pdf/1129.pdf

http://www.marchperf.com/pg50.html

http://www.alangrovecomponents.com/i...s/pspsheet.pdf

http://www.nostalgicairparts.com/ac/...pulleys-37.php

[suville]

I believe you will need the double alt. pulley I set up a 292 with PS and it used a double alt. pulley. usually the best way to convert a non PS to PS is to rob every piece from the front of the donor engine all pulleys.brkts etc that way you eliminate the frustration of trying to sort it all out. I know Frank (pickemup) in Olympia ,Wa can usually supply what you may need 292 stuff is rare but 194-250 is more common. Hope this is of sum help!

[NC67Chev]

Thanks Suville! I agree that I will need a double alternator pulley to make this work. Lesson learned for me in not getting all of the pulley's. Fortunately, I have a couple of leads to get me one, so I think I'll be okay.

[passthebuck]

Any luck with your pully issue NC67Chev?

[NGN]

Did you change the crank pulley using the Nove crank pulley . I seemed to notice even thouge the crank pulley on my 6 cly two fifty has has double groves already , it's not as wide as the power streeing crank pulley . The p/s crank pulley I got for my 6 banger is a grove then like a half inch space then a grove , the original non p/s crank pulley on my 6 has grove grove . I've yet to change over to p/s and not really sure why the differents in the pulleys but , that may be the off set you need . My parts are at work and I still need to learn how to post pic , I thuogh I had the measurment here at home but can't find them , wife clean out the junk draw . I could have the measurment Teusday afternoon as long as my tierd self remembers . Good luck and take care Nick

[NC67Chev]

Thanks for checking in with me. I think I'm all set with the pulleys. I ended up finding a guy that does nothing but rebuild alternators and starters. Anyway, he had some double GM alternator pulleys laying around. He charged me a total of $15 for the pulley and changed it out for no charge. Can't beat that. Anyway, everything lines up perfectly now. I'm hoping to get the conversion completed this weekend, that is if the wife and kids allow me to . I'll let you know when it's all done.