283 heads on 350

[toolboxchev]

Yea I know, they do not work that good. Flow tops out at 3500 according to some. Yet according to one site they have 69.8 cc chambers. 3731554 is the casting number and some reference sites claim it could have been on a dual quad motor. Anyone have any flow numbers on these heads?

I know I could go with World Products 72 cc chamber heads and have flow with a 2 inch intake valve. And hopefully still run pump gas, just having fun and keeping it economical.

Anyone ever done this? Or will they even bolt up??? I like staying old school so creating a ton of torque and hp is not the end objective here.

Thoughts on this would be greatly appreciated. I may also end up putting up a mouse motor!

[AcampoDave]

I believe 283 and also 305 heads have 58cc chambers. 283 heads lack hardened seats for unleaded. 305 high output heads are often used on 283's as a performance upgrade (even over the 283 power pack heads). They have bigger valves. I dont know about your specific part #, but in general, I personally wouldn't do it. There has got to be a few more good heavy casting 350 heads out there with 194 intakes waiting to be scooped up for cheap.

[Warrens69GMC]

Go with summit heads instead-

https://www.summitracing.com/parts/sum-152123/overview/

[Captainfab]

IMO there is nothing to be gained from bolting 283 heads onto a 350. I would just run the stock 350 heads if that's all you can afford.

[toolboxchev]

Thanks for the comments guys. I know the power and torque are needed for the weight and brick aerodynamics. I am aware of a couple of 283 blocks around and thinking the 302 would be a good candidate. Yet I would be needing the large journal crank and have not checked that yet. I am deciding if this is going to be a highway cruiser or end up an around town grocery getter.

Does anyone know if I could open up those 1.72 heads to accept a 1.94 valve? Keeping with tradition I like the thought of using origianl GM parts.

[Warrens69GMC]

So you want to have them fully reconditioned opened up for new valves, hardened seats installed - So roughly $800 to make them usable and still have less performance than a set of vortec heads / aftermarket heads.

[toolboxchev]

Originally Posted by Warrens69GMC

So you want to have them fully reconditioned opened up for new valves, hardened seats installed - So roughly $800 to make them usable and still have less performance than a set of vortec heads / aftermarket heads.

Last set of head I had done cost around 350 bucks, with a warranty. I got these cores on the cheap and they look to be in excellent shape for their age. Even matching Casting Numbers and Date codes.

[Captainfab]

Enlarging the valve seats, installing hardened exhaust seats, plus the port work necessary to make use of the larger valves, and all new valves is going to add quite a bit of cost to your last $350 valve job. What year of truck is this engine going into? Are heads with accessory holes going to be necessary?

[AcampoDave]

My 283 runs those 305 h.o. heads I mentioned earlier. The pt# ends in 416. They work well and didn't break the bank. I did a lot of research before I built my motor. It's a great all around driving motor and it's been all over California. But even with all the upgrades, a well tuned 350 could eat it's lunch. That doesn't bother my though because I built what I wanted which is a sweet touring motor that gets decent mpg's. If that kind of 283 interests you, I'd be happy to tell you more.

[toolboxchev]

Yes that does light my fancy a bit! Mileage with a bit of power. I have always heard that the 700r4 is not a very powerful transmission and would be a candidate with just a standard rebuild.

I have also thought about how to lighten the vehicle too. Getting rid of the canopy, bed mat will shed a few hundred pounds. Switching back to load range C tires and such. It is a 3/4 ton though.....

So Yeas please let me know what you have figured out! The accessory bolt holes may not be necessary, Electric Water Pump possibly, with mounting the alternator with maybe an aftermarket bracket. I wish to keep it old school, clean and tidy and oh yea its a '70

[AcampoDave]

http://67-72chevytrucks.com/vboard/s...=580055&page=2 I described it pretty well here in post #27. In retrospect, I'd say 250 h.p is a bit of an overstatement now that I have learned even more about other people's 283s which have actually been on a dyno but it still does everything I ask it to do. I should also add, that the manifod is an EPS Performer as opposed to the original Performer. Edit: I also foumd my cam card and it's actually a Melling MTC-1, but y'know,...pretty much the same cam as the Performer or the Summit 1102.

[GRX]

Originally Posted by Captainfab

Enlarging the valve seats, installing hardened exhaust seats, plus the port work necessary to make use of the larger valves, and all new valves is going to add quite a bit of cost to your last $350 valve job. What year of truck is this engine going into? Are heads with accessory holes going to be necessary?

^^ Full agreement. Do not forget the accessory holes. And changing to 1.94 valves is more than just larger valves & seats. The bowl and most of the port needs to be reworked as well. Otherwise you are wasting your time.

[toolboxchev]

Originally Posted by AcampoDave

http://67-72chevytrucks.com/vboard/s...=580055&page=2 I described it pretty well here in post #27. In retrospect, I'd say 250 h.p is a bit of an overstatement now that I have learned even more about other people's 283s which have actually been on a dyno but it still does everything I ask it to do. I should also add, that the manifod is an EPS Performer as opposed to the original Performer. Edit: I also foumd my cam card and it's actually a Melling MTC-1, but y'know,...pretty much the same cam as the Performer or the Summit 1102.

So the mouses speak to me. When I rebuild my 350, My buddy Tex swore up and down I had a 327 balancer on that motor. What he taught me was so simple. He was and is a believer in those small blocks. Funny you mention your MTC-1, I pulled a MTC-2 out of my 350 it used to pull stronger than the new cam I put in. I find the older wiser crowd sticks to what works. Not racing or impressing people with power. I do want longevity and what strikes me is the short stroke may be the way!

[AcampoDave]

Yep, and the old school cams don't cost too much either. In fact my whole motor didn't cost too much because the local engine re builder had initially built it for a different person who never came back to settle up for it. Nobody else seemed to be interested in purchasing it, so he just wanted to reclaim his investment in the thing. Since I was a long term customer, he made me an offer I couldn't refuse. I really like it. Sometimes, after a hard day at work, I love take it out on a freeway entrance or a country road and mash the pedal to the floor and just wind the snot out of it. And since it's not exactly a "torque monster", the "abuse sessions" don't reach speeds which could be hazerdous to others (or the rest of my drivetrain either for that matter)