Before I start rebuilding a 250 for my 63 Nova wagon, has anyone used the marine cams on the street? and which intake gives the best MPG, the Clifford single 4 bbl or the Offy? Planning on using a T-5 behind this engine and it will be used to travel to swap meets on the west coast and possibly pull and enclosed 5x8 trailer.

Welcome from Portland. I had the Offy and now have the Clifford but couldn't tell you which gives better mileage since my speedo has always been off. I wouldn't be inclined to use the T-5 for towing since they aren't known for their strength but as long as you're careful you should be ok.

I don't intend to bang the gears real hard, I have a drag car for that, just more intestred in reliabilty and driveability, so I'm trying to plan ahead of time of using hind sight.Comp Cams suggests using the 252H cam.

Brad might have meant the extra load put on the OD unit when towing & not gear changing etc.

If your not hauling a lot of (total weight) your probably okay as these transmissions came in the light trucks also.

Good luck.

OD on any tranny Is not ment For to be towing in.
It's not good to tow Esp. a AT tranny thats a good way to Burn it up. Plus it puts a heavier load on the motor/Lugging it. And you surly wouldn't have the power to Pass in OD (when towing)One thing I found out with my Van Vthing
Is that when towing In OD the MPGs die. It gets better MPGs when In drive Then in OD even On Flat Land not Hills.
Just My2cent.

It is nice to have the option of OD while towing. Just like in big OTR Semi's, some of eaton's trannys you could swap gears around and have a "Double Over" or two OD's instead of just one. No, you can't pulls hills in either one, but on the flat, and areas where you traveling down a small incline, it really shines as a fuel saver.

Of-course, a torquey engine will tear anything up, I could give speaches about 5.9(6BT) Cummins and NV4500's and towing in 5th gear, the engine can do it, tranny won't take it.

TP No need to quote/my 2cents
A 700R will NOT Live in OD while towing. This is something I found out when I took my 700R to a shop to have it rebuilt. (because it was Bad when I bought this Van)But anyway That was the very first Question He asked was I towing with it. He said Most people!!! like to leave it in OD when They are trying go get up Hills Or Have Heavy!! Loads. He said it just FLAT out Burns up The tranny & That 700Rs are NOT heat/Over heat friendly In anyway.
AND when it comes to the eaton tranny That Like APPLEs to Oranges. BIG difference/s

Larry
I agree totally with what you said about towing is not a great idea but since a lot of us do it this is what I have discovered since I got my first 700R4 in 1985.
I have had three different vehicles with 700R4s that I have towed trailers with there are two rules for making them last. 1 install a huge trans cooler and a transmission heat gauge. If you are towing in OD and heat guage starts to climb down shift. 2 If you hear the convertor start locking and unlocking down shift. I have pulled many a mile in OD by using these rules. Also if you are going to pull with a OD transmission you should have at least a 3.73 rear gear. People forget that a 3.08 rear gear be comes a 2.10 in OD while a 4.10 becomes a 2.80 in OD. I only had to toast one transmisssion to learn the above, since then I have never had a failure.
HEAT KILLS AUTOMATIC TRANSMISSIONS WITHOUT A DOUBT.

Theoretically the Offy would be better for your application as previous threads have stated it is better for low end power than the Clifford.

In my opinion, if you have a v6 version of the T-5 you should be ok pulling a light trailer behind the Chevy II, especially if you put some lower gears in the differential. Many have pulled small trailers with S-10s and Astro vans without difficulty. Do not know what your other plans are, but front disc brakes and at least an 8.2 five lug rear may make it a better tow rig and hopefully your trailer has brakes on it.

Big Bill
I think my Van Stock rear Is running a 3.42?? If i remember right? or just a little over But i know it's not a 3.73

Big Bill.
What formula are you using to calculate gear ratios with overdrive?

A 700R4 has a .30 OD ratio For the exact ratio take 70% of original ratio. This gives you the effect the OD has on your gear compared to 1 to 1 ratio in drive. I rounded off above 70% of 3.08is 2.16 a 4.10 = 2.87

The plan is to probably never tow over 1000 lbs. and that will only be a few times a year to the Portland Swap meet and to Hot August Nights and Bonnevile. The total gross weight should still be below the Camaro's gross so I should be okay. The final engine will be screwed together with the Offy 4 bbl. intake, an HEI, Comp Cams 252H cam and kit and a set of Langdon's cast headers. Sur glad Twisted 6 can really "speak'd da Engliss" I started to feel sorry for him.

what do you have a problem with??? But don't worry about feeling anything for me.Well if you can't read typo,s Sorry for your Luck.
( I'm not always a very good fart smeller=Smart speller) LOL