I think if you swap a Edlebrock performer and a Edelbrock 650 carb I would imagine you can get some more top end speed on the motor> This would bypass the govenor and allow the truck to go faster. I can get 60-65 in stock form now but would like 70-75.

 

Anything that has a 370 in it ought to stick to 65 mph.

You might be able to spin it harder that way, but you also need to look at the distributor to see if it also has a governor.

Do you know what RPMs you are dealing with? I would think you might start running into valve spring issues not too far above the stock governed speed.

 

I dont think these things are governed by the distributor. I think It's in the carb.

THat being said, maybe swapping to the Edle will be a bad idea. After more searching I think this thing doesnt turn more power after 3500 rpm.

The intake will help it I am sure. And will go that route with it.

Does anyone know if the govenor is in the carb or distributor for sure???

 

Many of the 370's and 429's used a electronic govenor . This system read engine RPM and acted as a RPM limiter. There were several variations that also had a carb feedback loop and controlled secondary operation. As far as changing to a edelbrock aluminum intake , don't waste your money . The stock intake will be just fine , a four hole spacer will help. On the 370 in my 81 L700 I ran a Holley list 1850 and a Edelbrock 650 . The edelbrock was the one that worked the best. About 4200RPM is about all that 370 is good for. Mine worked best at 3--3400 R's , any more than that was a waste of time. With the Edelbrock carb it was quicker to 3400 than the govenor carb was.
I later changed to a 460 and used a 750 Edelbrock and a 1in 4 hole spacer.
If you can rig up a cool air intake this will help alot.

Just Some Thoughts----- Hotwrench

 

Interesting! Thx>

How do you like the 460 in your rig???

Did you rig up a cold air intake on your rig?

 

Going from a 370 to a 429 or 460 is like nite and day. The mountain roads around here a fairly steep , the 370 went up in 3rd low, the 460 was pulling the same hill in either 4 hi or 5th low. Yes I rigged up a cold air intake it helped quite a bit . My truck was a mechanics truck with a hiab knuckle boom behind the cab , then a 10ft utility bed , lincloln welder , gas powered air compressor, torches , and all my hand tools. This truck weighed roughly
18,500 gross allowed 28,500. So it was loaded every where it went , it handled the load great and was very reliable. Rebuilt the 5spd trans once, broke 1 axle shaft , replaced the 370 when it started drinking oil . I put over 487,000 miles on this rig in 10 years.


Have A Great Day ---- Hotwrench

 

Wow that is a difference!

I can get a 460 pretty easy. I think I will do the swap.

What is your new top speed with this 460 set up?

 

Truck ran down the road comfortably at 60-65mph.

Have A Great Day ------ Hotwrench

 

Should have thought of/mentioned this earlier. You speed is limited not so much by the power of the 370, but by your gearing. If you are pushing 3500 rpm to run 65 now, you'll be pushing 3500 to run 65 with a 460.

Single speed rear axle? What trans?

What truck is this anyway?

 

Not sure what year of 370 you are working on but some have the govenor built into the distributor and some have have the rev's controled by the carb. My 1988 F-600 w/370 the govenor was built into the carb.
I replaced the carb with a Holley 4412 2bbl that I scored at a garage sale for $5 bucks. That alone made a big differance. Then I installed a Summit Racing CDI ignition unit with a revlimiter and a Accel big yellow super coil. Not only did I get a lot more low end grunt but my mileage increased from 6-1/2 mpg to 9 mpg on the highway empty.
The big thing about reving these motors hard is you can explode the big heavy flywheel.

 

Regardless of which engine you chose, figure out what speed your tires are rated for. MANY, but not all larger truck tires are only rated for 60 or 65 mph.

Also, check your states laws - many have 10k to 16k GVW and up rated truck speed limits in the 55 to 60 mph range.

No sense to get a ticket or risk hurting a innocent victim if you blow out a tire at high speed and take out that Honda full of kids.

That said, I have always thought about swapping in a EFI 460 in place of the 370 - Personally I think that would be the way to go if swapping engines. No more poor running when cold!

Good luck with your project

David