|06-30-2011 10:20 PM|
Thought I'd share a few photos on the difference in distributors between a '75 TD427 and a mid 80's BBC distributor. My findings is that the LENGTHS are identical. The reason a regular ol HEI won't simply drop in a tall deck is due to the oil pump drive as mentioned above.
The medium duty truck's 427 distributor housing is cast iron. It has no wear a'tall.
If a guy really wanted to, he could grind the rivets from the TD427 gear and then grind the drive tab off the HEI shaft and fasten the TD427 gear by either re-riveting or roll pin. If a guy wanted to...
on edit: Found some n.o.s. Blue Streak parts and they're on the way. Cap, points, condenser, rotor and coil. Sometimes ebay works out for the better.
BTW Echlin is now Standard Motor Products stuff (bought out) SMP still does the Blue Streak line but Echlin is the lower line SMP. (as per NAPA counter guy)
|06-23-2011 01:12 PM|
|06-23-2011 11:05 AM|
Read more on the distributor length deal and it appears that the TD427 (& 366) even has a different oil pump drive shaft 'interface' -as in, Car and light truck is slotted, and TD/industrial/marine is round with 2 flats.
While I have the carb and ignition torn down, I'm going to pull the distributor for a checkup anyway. Then I will know for sure the difference in length, and if it's even feasible to MOD a typical HEI to work. (slip collar, shaft and or gear)
|06-23-2011 10:32 AM|
|06-22-2011 10:21 PM|
If you are the worrying sort, use a tach w/a shift light or even a shift light alone to let you know when to grab a gear.
The 3310 carb will only give you what the engine demands (vacuum secondary) so being "too big" isn't a problem- even on your "industrial" TD 427.
The HEI distributor is another matter. The TD block takes a longer distributor than a 'normal' SBC or BBC engine. There are aftermarket HEI distributors that will work fine, though. Or you can add an electronic points replacement that uses the original distributor.
|06-22-2011 04:09 PM|
|blue54||That will work, but isn't a 3310 a little large. I would lean toward something in the 600cfm range. The rev limiter etc will work great.|
|06-22-2011 04:05 PM|
What to do, what to do....
Well I have NO problem ditching the points in this dump truck. Zero sentimental value... The fact that it has no tilt nose my sway my decision. The thing is a real SOB to work on under the hood.
The distributor has this 1/4 inch line that runs to the carb, possibly vacuum or pressure for the governor'd Holley.
I tore down the carb mentioned in this thread:
It's a pretty complex little booger. It appears to have an OIL capacity on the topside of 2 of the 3 diaphragms. Strange....
If anybody has messed with these or knows how the hell it works, please post up.
Here's what I may do. I have a nice gently used Holley 3310 750 on the shelf. Also I have a spare HEI that will need a going through. I might just get a rev limiter module for the HEI and bolt on the 3310 and call it 'good'.. What do you guys think?
|06-20-2011 04:30 AM|
Points distributors will tend to wear the bushings faster than an electronic unit due to side loading from the spring, which is accelerated with the high performance points like the Echlin Gold ( which is all I used back in the day).
I have noticed the quality of points seems to have deteriorated in the last couple decades. All of them I have installed in the last few years practically go closed in the first 500-1000 miles due to the crappy material in the rubbing block. After the get run in and reset they seem to last ok. The last vehicle I had with them got a petronix, best move I made.
|06-20-2011 02:00 AM|
|matt167||Yep. Standard motor products, Blue Streak line|
|06-19-2011 04:03 PM|
|cranky1||IIRC, Standard Motor Products make them....|
|06-19-2011 03:56 PM|
Pertronixs i have used them a few times and they are a pretty good investment IMHO and you can still keep a set of points around just in case and swap right back no problem.JMO
|06-19-2011 03:50 PM|
Yeah the reason for even messing with points is because this truck has the governor setup. It's got that funky Holley carb that is plumbed to the point type distributor. They work in conjunction to govern engine revs. Common on the medium duty GM's.
Usually an HEI swap would do the trick, but I'd like to keep the governor intact.
The pertronics deal is a neat piece.
Curious, is the Blue Streak points known by any other brand? Can't find them on Rock Auto..
|06-19-2011 03:19 PM|
|cranky1||There are several that run points on unrestored cars or want to stay 'completely' original and doing a tuneup isn't hard. If you're not running high rpm, don't use the points with the high spring rate then you won't have to dwell it so often. The high spring rate 'anti bounce' points wears the rubbing block faster. My tuneups lasted well over a year on my daily driver 66 Belvedere. Part of that was 'over' tuning or setting the points a little wide and gaping the plugs a little tight and letting the tune drive in and used good parts. I don't mind doing a tuneup actually....plus I don't have to carry spare pickups, ECM's and the like.|
|06-17-2011 02:24 PM|
|06-17-2011 01:13 PM|
Say bye-bye to the dwell
If your distributor is in good shape, with no wobble in the breaker plate and no excessive thrust in the distributor shaft, a Pertonix kit is the only way to fly. You will not have to stand on your head setting the dwell every few weeks.
The best available points are NAPA Gold (Echlin) because have a 38 oz spring to prevent point bounce at high RPM. They are just like the old ACDelco D112P points that worked so well in the high performance SB & BB Chevy engines with point type ignition systems until they were finally discontinued in 1985, but they required frequent dwell adjustments. The good ACDelco D112P points were replaced by ACDelco D106P which are nothing but junk, have an 18 oz. spring and are made by Mexicans.
|This thread has more than 15 replies. Click here to review the whole thread.|