oem 1.88 valve question

Im putting a set of 1.88 in place of a std. 318 intake valve and just dug out my 1.88 valves.

The length is correct, a test lap shows great pattern but then I noticed its got a 4 groove lock.

I tossed the boxes long ago.

Did they make a 4 groove 1.88 intake or do I have some sort of 1.88 ex. valve? It does not have a wider margin then the 1.78 oem?

So whats up? And if this is in reality an ex valve, could I still use it as a HD intake?

Any input would be great as im not well versed in this area.

Oem 1.78 is 117 grams, this 1.88 is 123 grams.

Thanks.

They come both ways.
Most are 4 groove.

Just get the correct locks and you’re good to go.

If the seats haven’t been cut for that size valve, there isn’t going to be really any benefit to using them, and it will likely create a spring installed height and/or a valve tip height problem.

Thank you sir, as always!

Agree, both ways.

The 360's 1.88 is a great upgrade to 273 and 318 heads if you need new valves. Yes the seat will need a new cut and that is a good thing anyway. That is the biggest valve you can put in a 273 without notching the cylinder. I have a set of ported closed chamber 273 heads with 1.88/1.60 on my LRT 360. Not the best flowing heads but snappy.

Try a backcut if you use the Mopar OEM type valves, That picked up flow a bit on my 273 heads I was messing with a couple of years ago. We got it flowing about 180 cfm @ .420" lift without messing the bowl cuts. I ran out of money on that project before we tried any valve job angles, etc. Not bad for a stock head with 1.78" intake valves.