I am new to this forum so let me start by saying Hi



Now I need some help :help: .

I have a 1991 Suburban that I spun a bearing, so I got another engine, can't find year of block, casting #3970010. It was a carburated engine I want to keep FI, The intakes don't match exactly. everything lines up exactly except the 4 center bolts, 2 on each side, they are on a differant plane I guess you would say, The "new" block all the intake bolts are the same angle, the 91 the center 4 are differant? Is there a adapter plate that would allow me to use the old carb intake with the TBI??

<TABLE id=AutoNumber1 style="BORDER-COLLAPSE: collapse" borderColor=#111111 height=361 cellSpacing=0 cellPadding=0 width=559 border=1><TBODY><TR><TD align=middle width=122 height=9>3970010</TD><TD align=middle width=74 height=9>350</TD><TD align=middle width=99 height=9>1969 - 80</TD></TR></TBODY></TABLE>

3970010 350 1969 - 80 sorry first post wrong format! Thats a common serial number!

Up through 1986, the bolt pattern on all small block Chevy engines was exactly the same. From 1987 through 1995, the four center mounting bolt holes (two on each side) were at a different angle. This change applied only to Chevy cast iron heads. The aluminum heads were the same. Whereas every other manifold company has a few additional models to fit these later heads, every one of Professional Products' SB Chevy manifolds (except Vortec models) will fit all years up through 1995. This is accomplished by slotting these four center holes and supplying drop in bushings which change the bolt hole angle to fit the late heads. On the early heads, you simply use flat washers on the slotted holes. Note this does not apply to the Vortec manifolds, which do not have the four center holes.

Thanks for replies.


I filed the intake holes to achieve the proper angle and figured I could have some spacers or bushings machine so bolts will seat properly, the problem is I am tight on space to be able to get a longer bolt in. So I decided I would find an adaptor plate, which I did Holley makes one, the only problem with this is a few differences in the intakes, such as fitting for heater core line, another is for EGR, and a vac line, My new question is -- the chamber below the carb is smaller, less volume than the 91 FI intake, will that be a problem?? I figure I can tap EGR and vac lines if needed into intake, just curious about the difference in size.

Also can you pin-point the year of block? or just a decade span??


Thanks allot guys

ZMAN,
You know your stuff!!!

PS- the intake will seal up fine if you dont use the 4 center holes (just plug them to prevent oil from getting out)

experience is the best teacher

Well I got it fixed up, I bought some 3/8 studs cut them to size, cut some 1 1/2" fender washers to fit and cut some steel rod, that happened to be hollow with 3/8 id, on an angle put it all together looks good and sealed good, solved my intake problem.

Now on to the trans, I was thinking of putting in a shift kit while I had it out, any suggestions on that.

Thanks

i put a shift kit in my last truck, an 89 k1500. i used the B&M tow/haul one. not only was it a huge pain in the ass and messy to install, but was real snappy afterwards. i have ridden in street cars with shift kits and this wasnt much more mild. not comfortable for everyday street driving. i would not recommend it myself unless its a tow only vehicle. just my experience...

i do like the idea of the B&M electronic option for the later 90s trucks because there is a switch in the cab that allows you to choose between stock, street and tow.

The electronic shift kit works well. the highest level was a little too much for the street but the street setting was good. It was a 2 wire hookup if i remember correctly.