[tommytempest]

so I'm putting a 468 in a 70 Nova, and it looks to me like the small block mounts will work just fine. I bolted the block to a TH350 and dropped them in on the original mounts and everything lined up fine, yet I see on Ebay that there is a vendor selling big block nova mounts, (the part that mounts to the frame). Anyone know? They may be taller than the SB mounts to allow more room for exhaust? Further forward? Not sure. I didn't have the hood on or any of the front accessories or exhaust, so I guess there could be problems there, but the trans mount lined right up and the motor mount bolts slid right in with all the small block stuff............Any other issues I'm going to run into on this conversion? I realize I will probably blow out the rear end and wrap the rear springs, but I'll upgrade back there eventually. I have frame connectors on order and a radiator, but am planning on running the TH350. A buddy of mine claims he can build them to hold up to 500HP? I figure I'll try it and if not I'll have a TH400 built up after I blow the TH350. What else am I missing guys? It actually looked like an HEI would fit with the big block also.
Thanks in advance!
Tom

 

[DoubleVision]

If I remember correctly, the BB mounts make the engine sit lower, which was correct for clearence issues in certain vehicles with the valve covers hitting the power brake booster as well as other clearence issues. It`s been so long I really can`t remember what else. I do remember in most cases the small block mounts sat too high and caused clearence problems.

 

[35chev/302gmc]

The B.B mounts make the engine sit lower and over to the right(pass side)
Headers wont clear the streeing box with the S.B mounts

 

[tommytempest]

Wow! Quick responses! Thanks guys. I know the head was damn close to the power steering box when I had things mocked up, but I though maybe the ps bb nova headers somehow went around that. Good info! I will get the big block mounts ordered today! Any other issues anyone can think of?
Thanks again!
Tom

 

[jimfulco]

Big-blocks also got a different trans crossmember, so the trans mount is also located a little to the right, to match the motor mounting. '67-'69 Camaros use the same subframe as your car, so you can use a Camaro crossmember.

If you plan to use the T-350 with a BBC, you'll need to use a big-block manual-transmission crossmember. Big-block cars never got a T-350 from the factory, only a T-400, but the T-350 will mount to the same holes that a stick-shift does. Look at the bottom of your current crossmember and notice that the cutout where you find the trans mount bolts is oval-shaped. On the BBC crossmember, that cutout is more squared-off. You might be able to modify yours to work, if you can't find the BBC unit.

Here's a link to a new repro one: http://rickscamaros.com/cgi-local/SoftCart.exe/online-store/scstore/blankp.htm?E+scstore (click on transmission, then click on crossmember down at the bottom)

 

[tommytempest]

Thanks Jimfulco! Good info. Thanks for the link. Maybe I'll just go with a TH400, shorten my driveshaft and install a kickdown switch on the carb. Still undecided about that. Either way, thanks for the info on the crossmember being different, looks like I'll be needing one of those as well!

Now how about my intake? I currently have a Weiand stealth oval port intake which is basically a high rise dual plane. I would like to use a Victor Jr, but am I going to have hood clearance with either one of those or am I looking at cutting the hood? I plan on using either the Comp Magnum 280 or 292 cam with 9.5:1 compression and am shooting for 500+HP. (468ci)