[jamesg63]

Hi I have a question, I have a factory 360 out of a Dodge Motorhome. It is a 2bbl setup, Without any modifications to the engine how beneficial(powerwise) would it be to upgrade to a 4bbl. Or should I just stay with the 2 bbl until I am able to add a different cam,headers,etc.

 

[dana44]

Well, a stock intake and 4bbl will add about 25hp, but you can verify that through the factory differences in a book, or even an internet search. When it comes time to do the swap, save the money up, get all the parts like cam and lifters, dual exhaust system, headers can add about 15hp but you would not use it enough to make the cost worth it on the street really, dual exhaust will work just as well plus save a ton of money and headaches, and do the work all at once so you only need one gasket set. It may take a little longer, but talk about more enjoyable when done. Oh, and the truck cam in the engine now probably is set up for low end torque more than top end power, so it should at this point in time do decent on mileage.

 

[tazdevil]

All that and you will still have low compression and low flow heads. I would recommend doing a complete overhaul when the money is there. Bore and hone, refinish crank and then the right parts. The 360 is a great engine to modify, with low end torque and lots of power enhancing parts available. It's tough, but wait until you can do it right, and prevent "swapper's remorse". I speak from experience.

 

[jamesg63]

OK I found a set of J Heads from a 1978. Are these good? Will they give me more power than my stock 1973 Heads? Will these work for my application? Sorry for all the questions. Thanks

 

[dana44]

If the valves are the same size, there will be no difference.

 

[jamesg63]

The current heads on the engine have 2 separate casting numbers? They are 4027163 and 4027593. The heads I found have a casting # of 4027569-a. Would I be better off with just keeping mine? Sorry to ask so many questions but this will be my first Mopar build and I wanna get it right.
Thanks

 

[dana44]

No problem with the questions. It is extremely hard to say if the heads are the same or not, but at this point, why chance it. I would get two heads that are the same casting. There may not be any difference, but, why chance it, right?

 

[jamesg63]

Thanks Dyna, so basically the larger valves are the better heads?

 

[dana44]

360s came in 1.88 and 2.02s. If performance is the idea, yeah, 2.02s are better. The Magnums went to a 1.925 intake across the board and it is a great valve size for all the V6 and V8 engines (3.9, 5.2 and 5.9). Too bad they are a different length and diameter stem and won't fit in the LA heads without a lot of work. Back to the 2.02 heads, they were known to be good heads right out of the box, unbelievable when properly ported.

 

[jamesg63]

I wanna be able to run down the strip without embarrasment on occation.

 

[dana44]

Both will do pretty well, the 2.02s are worth an extra 30 or so hp.