wanted to summarize stuff in case someone did not want to read all the posts....
'86 and '87 (intercooled) turbo Buicks used lower radiator hose GM 25523616 which is a direct match to Dayco 71756.
'84 and '85 hot air turbo buicks AND the NA 231 V6 applications used lower radiator hose GM 1261444 and 1264041 which are a direct match to Dayco 71083.
The difference between the two hose designs is that the 71756 has a straight section about 6 inches long leading into the water pump while the 71083 has an additional offset bend here. The Dayco 71083 has a displacement length 4 inches longer than the 71756.
The hot air cars did not have an oil cooler adapter or the accompanying oil hoses at the filter so the space occupied by that longer hose is not a problem. Referencing the pic in post 29 by
monteperformanc, there is no place to loose 4 inches of hose on the '86 - '87 TBs using the factory oil cooler and stock or aftermarket headers. Lil Truck's 2nd pic in post 33 shows the 71083 installed with TA headers. It only fits because their are no factory oil cooler lines to work around. The offset in this 71083 hose works well to get more clearance to the TA headers but again, won't fit if using stock oil cooler and oil hoses.
The problem is that brick and mortar stores, on-line stores and some TB vendors are mixing up these hoses. AND that is a big problem. Search by year, make, model, engine, aspiration...the results are a complete crapshoot.
Rock Auto....search for 87 TB => results are Gates 21211, Continental 61043, Delco 26069X. These 3 all have the offset and are the same as Dayco 71083. All 3 are WRONG.
.........................................................................Dayco 71756 is the only correct hose and cross references directly with GM original hose 25523616.
.....................search for 86 TB => results are Gates 21211, Continental 61043, Delco 26069X. WRONG. The correct Dayco 71756 is not even listed as the Dayco rep I spoke with noted the 71756 is only in their system for an 87 TB.
.....................search for 84 or 85 TB => results are Gates 21211, Continental 61043, Delco 26069X and Dayco 71083. Well, the hot air cars are correct.
Advance Auto Parts.....search for 87 TB => result is Dayco 71756.
.....................................search for 86 TB => the only result is for a flex hose, Dayco 81221 - a 30 inch long hose!
There is no mention of Dayco 71756 as I noted above, Dayco only has 71756 applying to 1 vehicle - the 87 TB.
.....................................search for 84 or 85 TB => result is Dayco 71083. Hot air cars are correct here also.
NAPA...........search for an 87 TB or any TB => NBH 7922 - the hose with the offset curve. only good for NA and hot air. 7922 is a direct crossover to Dayco 71083.
Autozone.....search for 87 TB => result is Dayco 71756.
.....................................search for 86 TB => the only result is for a flex hose, Dayco 81221. There is no mention of Dayco 71756 as I noted above, Dayco only has 71756 applying to 1 vehicle - the 87 TB.
.....................................search for 84 or 85 TB => result is Dayco 71083. Hot air cars are correct here also.
OReilly's only lists the Gates 21211. Wrong for 86 and 87 TB's.
HIghway Stars pic shows the offset hose, 71083 or equivalent, which is wrong and he says it is an exact match to the original 25523616. Not true.
Kirban's part #6842 pic shows the offset hose noting it is correct for 84-87 TBs. Not so. Hot airs used that hose, intercooled cars did not.
You saw what Ttype6 noted about how searching on Summit worked out. not.
I could go on but I think the reader get the point. I'll call some of the TB vendors next week to offer this info. But many times vendors get salty no matter how nicely you try to help them make improvements or corrections.