[muscle_collector]

here are the same pics but on the blue block

[muscle_collector]

this is the two blocks where the lug is. the one has a large 9 stamped or recessed molded into it where the other has what looks like small circles.

[muscle_collector]

this is very interesting. they both have the same stamped number at the back by the distributor hole under where the "71" is cast they are A1F10
what in the world could this be???

[muscle_collector]

here is the valley on the black block. it appears to have a brazing / filled in a few spots

[muscle_collector]

I appreciate all the input on these two blocks. ive owned them for 30 something years (getting close to 40). it is really crazy that I have never until now noticed some of the things the same and then things different.

[tom s]

They are the small dist hole.My std dist is like 1.370 dia and the V is 1.625.Tom

[unruhjonny]

Originally Posted by tom s

They are the small dist hole.My std dist is like 1.370 dia and the V is 1.625.Tom

With all due respect to whom I regard as "the RAV guy" here:

Maybe I am seeing it wrong;
It looks like the "black block" distributor hole is measured 1.5", while the 'blue block" distributor hole is measured at more than 1.5".
Granted, a tape measurement like that can read funny just by the angle of the picture - but I would think that if std is 1.37", then neither should have an apparent measurement of 1.5" or more.

I would think that it's easier to measure that way and have too small of a measurement rather than too large of a measurement;

Am I wrong?

1.37" = 1-6/16"
1.625" = 1-10/16"

[sdbob]

Are any of the lifter oil feed holes taped? PMD had a sheet with recommended mods to 303 blocks and this was one of them restrict oil to lifters. I have a copy.

[tom s]

Really dont know why they needed to be restricted with factory lifters?Pontiac solid lifters had a pin sized hole in them.When using other than factory with a 80 lb pump it would make sense.Factory solid lifter applications recommend high idle speed for the reason of oil to the springs.Tom

[tom s]

OR 1 3/8 and 1 5/8?I guess the owner could get a true number by just putting a std dist or a V-455SD dizzy in the block.I know the 303 std deck block I just bought has the std hole.Remember they were just a destroked RA IV!Tom

[tom s]

Back to the OP stuff.Tom

[muscle_collector]

Originally Posted by unruhjonny

With all due respect to whom I regard as "the RAV guy" here:

Maybe I am seeing it wrong;
It looks like the "black block" distributor hole is measured 1.5", while the 'blue block" distributor hole is measured at more than 1.5".
Granted, a tape measurement like that can read funny just by the angle of the picture - but I would think that if std is 1.37", then neither should have an apparent measurement of 1.5" or more.

I would think that it's easier to measure that way and have too small of a measurement rather than too large of a measurement;

Am I wrong?

1.37" = 1-6/16"
1.625" = 1-10/16"

you are correct the holes are a little bigger than 1.5"

[unruhjonny]

Originally Posted by tom s

OR 1 3/8 and 1 5/8?I guess the owner could get a true number by just putting a std dist or a V-455SD dizzy in the block.I know the 303 std deck block I just bought has the std hole.Remember they were just a destroked RA IV!Tom

yup, I just used sixteenth, because I use that every day, and although the measuring tape appears to go the thirty-seconds, that can be a bit hard to discern.

Man oh man, your "garage" must be a treasure trove of super rare Pontiac stuff.

Originally Posted by muscle_collector

you are correct the holes are a little bigger than 1.5"

ok, so then that does seem to point to them being machined for oversized distributors - which (iirc) was only RAV or SD455.

[Baron Von Zeppelin]

They might could be left-over/surplus pieces from David Pearson 1971 Nascar endeavor with a 71 GTO.

Wild guess from the hip , but its about the only thing i can think of that was going on that might have had backdoor tunnel-port hardware support in that time frame.

With the coincidences, seems like an organized effort was being made towards something. More than just hobby shop stuff




Race Site Cars St Fin # Sponsor / Owner Car Laps Money Status Led
1 Riverside 40 16 35 17 Holman-Moody Racing
Crew Chief: Jake Elder Ford 25/191 1,165 engine 20
3 Daytona 31 4 1 17 Holman-Moody Racing
Crew Chief: Jake Elder Mercury 50/50 1,200 running 16
4 Daytona 40 4 4 17 Purolator Filters (Holman-Moody Racing)
Crew Chief: Jake Elder Mercury 199/200 4,225 running 6
8 Hickory 22 3 2 44 Giachetti Brothers (Richard Giachetti)
Crew Chief: Jake Elder Ford 275/276 1,500 running 1
9 Bristol 30 1 1 17 Holman-Moody Racing
Crew Chief: Jake Elder Ford 500/500 6,120 running 133
10 Atlanta 40 6 4 17 Purolator Special (Holman-Moody Racing)
Crew Chief: Jake Elder Ford 327/328 4,490 running 36
12 Greenville 26 1 2 17 Purolator (Holman-Moody Racing)
Crew Chief: Jake Elder Ford 198/200 1,030 running 19
14 North Wilkesboro 30 2 2 17 Holman Moody (Holman-Moody Racing)
Crew Chief: Jake Elder Ford 399/400 2,570 running 4
15 Martinsville 30 5 2 17 Holman-Moody (Holman-Moody Racing)
Crew Chief: Jake Elder Ford 500/500 2,550 running 14
16 Darlington 36 2 31 17 Holman-Moody (Holman-Moody Racing)
Crew Chief: Jake Elder Mercury 30/293 1,075 steering 3
18 Talladega 50 8 43 33 C.V. Enterprises (Ray Nichels) Pontiac 19/188 1,175 engine 0
21 Charlotte 40 14 34 33 C.V. Enterprises (Ray Nichels) Pontiac 94/400 1,055 oil leak 0
23 Michigan 40 19 33 33 C.V. Enterprises (Ray Nichels) Pontiac 68/197 650 ignition 0
27 Daytona 40 7 8 17 C.V. Enterprises (Ray Nichels) Plymouth 157/160 1,250 running 0
40 Darlington 40 13 35 17 C.V. Enterprises (Ray Nichels) Pontiac 50/367 795 engine 0
44 Rockingham 41 8 36 99 Nichels-Goldsmith (Ray Nichels) Plymouth 92/492 585 crash 0
48 College Station 49 6 48 17 C.V. Enterprises (Ray Nichels) Pontiac 15/250 575 overheating 0

DNQs, WDs or driver changes (DC)
37 Talladega DNQ 17 Pontiac

[tom s]

BVZ,the 366 block had its own casting number.The std bore on it was 4.155,they have reinforced lifter bores.I think these blocks like the one I just bought lean more to a 303 std deck BUT as said I never say never on engineering stuff.Would be interested in what the actual bore is.My block has been shipped so will learn more when it arrives.Tom

[muscle_collector]

I don't have a clue what these were built for. obviously something special, but that's why I posted it. crazy thing I never realized they had the same ds, date codes, stampings until just recently I was on the phone with boss and happened to look at one and said I had another one and then what the heck???? these are identical. hmmmm what in the world are these.

[74SDformula]

MC, thanks for sharing photos of those two blocks. I too have wondered about the stampings I have sometimes seen on blocks by the distributor hole. However I have only seen these stampings on blocks cast in 1971 and /or 1972. Here is another photo of a stamping but you have to look close.

[tom s]

URJ,from what I have learned that the 303s and 366 blocks even with RA IV heads got the larger dist.You can tell what the block was or intended for by the placement of the valve reliefs.My 366 was for sure RA IV as it had IV heads on it when the previous owner received it.I started to build it as a IV but decided against it and do it as a V.Will know more about the 303 block when its actually in my hands.As said,never say never or always.Tom

[tom s]

Gary,do you see any valve reliefs in any of the bores?Also any pics of the rear cam tunnel?Tom

[tom s]

I see the blue block actually has 400 cast into it.Blk?Tom