I am swapping an 85 351HO/C6 combo into a 79 F100 that has a 302/C4 now. I have a set of NICE DOOE heads that I could put on this motor. Are the original heads on this motor ok, or would the DOOE heads work better? I think I would have to buy hardened pushrods and new rockerarms for the swap. Might be better to sell the heads and use the money for upgrades on the HO. Thanks for any help and answers!
P.S. Just found this site yesterday, this is great!
I have a 85 351W HO in my Bronco w/ a C6 and it ran awsome until I blew an oil cooler line and blew up. I am now rebuilding it and using thstock head because they worked fine for me. I do recommend you get the heads serviced w/ nex valve seals and seats but other then that I would see the other heads and buy and Edelbrock intake.
If I were you I would check with a knowledgable source before swapping heads. If my memory serves me the D0OE heads in question are 58-60cc heads and the factory heads on your HO are 67cc and have similar if not marginally larger valves. The valves withstanding the older heads would put a 8:1 ratio engine (yours) closer to 10:1 and although you would feel far more low end pull, you would have to run race gas to keep it from detonating badly.
I bought an 85 f150 4x4 w/c6 and 3:50 gear's I put 135,000 miles on eng w/o problem. However it was not ever a match on performance with 85 or 86 f150 with a inj 302and aodtran. I suggest keep it matched up. When you remove head's be ready to say HOW FAR DO I GO.ITMay be time to overhawl and put '96 roller cam.concern's: computer,oxg. sensor YOU know these were the remaining year's for mixed technology8
PS What are these head'd off of?
The DOOE heads do have around a 60cc chamber so they would raise your compression to around 9.4 to 1 which is perfectly acceptable on cheap pump gas as long as you don't dial in too much advance. The stock valve sizes on these heads are 1.84-I and 1.54-E. The heads on your 85 HO are likely only 1.78-I and 1.46-E with about a 68-70cc chamber.
If I were in your shoes I would bolt on the DOOEs. If you decide against using them let me know, I may be interested.
DannyP
Thanks for the help. I have talked to a pro engine builder and we have decided to use the original heads on the engine. These are factory 302 heads with a 70 cc chamber. Guess they used the 302 heads for better low end torque. I had the block decked to 5 thousands in order to get a square block and raise my compression to 8.9 to 1. Using the DOOE heads would have raised my ratio higher than wanted for a street/pulling engine. I have added a Comp cams dual pattern 4x4 cam and an Edelbrock intake to the combination. Should make for good off-idle torque.. Also we went through the heads and upgraded the springs and seals. I will probably sell the DOOE heads--completely upgraded SS valves, screw in studs, new bronze guides, ported, etc.
DOOE heads on a 85 351HO
