Olds 403 Buildup

[TBRtat2]

For me, I am running a remote oil filter (i didnt like how close the filter was to the headers) but I havent mounted a oil cooler on mine yet, (it has not needed it yet, but i have only had it in the cold).
But if i did it would be easy, just run in line with the remote oil filter.
There are kits for oil coolers, that mount a adpter between the filter and the mount, but space is the issue with those.

Also check your trans temps, I have heard from a few guys over the years that had heat issues with a 403 but only under heavy loads (towing, etc.), they found out there trans's where running hot, and in turn heated the motor thru direct heat tranfer (trans case to engine block), and by heating the coolant in the radiator (from the trans cooler in the radiator).

As for my radiator, i am running the stock "Heavy duty" aluminum replacment for a a cutlass with a 307 from my local auto parts store. its a 2 row, with decent size rows.

 

[olds307 and 403]

Did they deck the block any after installing the pistons? How much of an overbore? It will make a big difference on actual compression ratio.

 

[foxtrot]

I did wind up procuring the #5 heads! I did sort of a swap of the 403 heads ++ $$! The number #5 heads are also ported && polished! I'm hoping that this is worth the $$ because it wasn't cheap! Mum's the word on the $$! As I said before, I'm not bringing this auto to the qtr just want to feel it in the seat of my pants. I think that this will be accomplished now. I'm done spending money. 🙂

 

[beeterolds]

i had a 403 with #7 heads, i never had any cooling problems, i ran a 7blade clutch fan with a 3 row diesel radiator..no problems to speak of