ok here goes....79 bronco, 351M, C6, front diff dana 44, headman headers, 2.5" collectors, true duals with turbo exhaust (no X over or H), 4bbl edelbrock intake, edelbrock 650, 6" lift, 35x13.5x15 tires.


previous owner claims the engine was overhauled 45k miles ago and a "camper special" cam was installed. also claims the transmission was overhauled 55k miles ago. he claims about 350hp at the wheel but I'm skeptical. everything works very well.


1) previous owner states that everything is original equip (less the cam), so my first question is, would anyone know what the gear ratio is in the rear diff and what kind of diff that is?


2) with the list of equipment I gave, what would be the best timing set for this? 10 to 12 deg or 6 to 8 deg?


3) going approx. 65mph at 2600 rpm, the oil pressure gets high (about 75 to 80% of the stock guage), should I be concerned or should I just slow it down?


4) from question 3, the eng temp gets up there as well! I am considering removing the thermostat and seeing if it continues. any suggestions?


5) I want to rejet the carb to a smaller jet because this setup is burning rich. no matter how I tune this carb it still burns too rich. the lowest stock jets that this 650 came with are .98. i think I want to drop it down to about an .88 . any thoughts.


thank you for your time and input.

 

Well I can tell you that MOST of that entire engine is not stock.
#1 these came with a few different ratios off the lot, 3.5:1 and wide open was the most common but youl have to look at the tags on the diffs themselves to know for sure. judging by your "65 MPH at 2600 RPM and 35s and a 1:1 3rd gear ratio in your C6" though I would say you probably have 4.10s instead. I think it was a rare stock option but it is also a very common upgrade with 35s
the rest of the questions are too hard to answer without being there myself but yes, I would slow down. (cant hurt to go slower) but I couldn't say about the oil pressure aside from that. yes, always be concerned if you have overheating problems when you arent standing still in traffic, have you tried flushing your system? I always do ALL fluids when I buy a new rig just to be safe. (again, cant hurt) so yeah, Im pretty positive you have 4.10s and I am absolutely no help for the other questions lol. Good luck.

 

I would install a manual gauge set to make sure the factory gauges are correct before doing anything major. My '78 factory gauges are way off! The stock temp said my engine was way hot but I could hold my bare finger in the radiator, lukewarm.

 

^^ X 2 what Greg said